Handover for closed access group

ABSTRACT

A first base station receives, from a second base station, a message comprising a network slice configuration parameter associated with a closed access group that one or more cells of the second base station support. The first base station determines based on the network slice configuration parameter, a handover for the wireless device to a cell of the one or more cells. The first base station sends, to the second base station, a request message for the handover, the request message comprising an identifier of the closed access group of the wireless device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/825,179, filed Mar. 28, 2019, which is hereby incorporated byreference in its entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present inventionare described herein with reference to the drawings.

FIG. 1 is a diagram of an example 5G system architecture as per anaspect of an embodiment of the present disclosure.

FIG. 2 is a diagram of an example 5G System architecture as per anaspect of an embodiment of the present disclosure.

FIG. 3 is a system diagram of an example wireless device and a networknode in a 5G system as per an aspect of an embodiment of the presentdisclosure.

FIG. 4 is a system diagram of an example network node as per an aspectof an embodiment of the present disclosure.

FIG. 5A and FIG. 5B depict two registration management state models inUE 100 and AMF 155 as per an aspect of embodiments of the presentdisclosure.

FIG. 6A and FIG. 6B depict two connection management state models in UE100 and AMF 155 as per an aspect of embodiments of the presentdisclosure.

FIG. 7 is diagram for classification and marking traffic as per anaspect of an embodiment of the present disclosure.

FIGS. 8-21 are example call flows as per aspects of embodiments of thepresent disclosure.

FIGS. 22-34 are example diagrams as per aspects of embodiments of thepresent disclosure.

DETAILED DESCRIPTION OF EXAMPLES

Example embodiments of the present invention enable implementation ofenhanced features and functionalities in 5G systems. Embodiments of thetechnology disclosed herein may be employed in the technical field of 5Gsystems and network slicing for communication systems. Moreparticularly, the embodiments of the technology disclosed herein mayrelate to 5G core network and 5G systems for network slicing incommunication systems. Throughout the present disclosure, UE, wirelessdevice, and mobile device are used interchangeably.

The following acronyms are used throughout the present disclosure:

-   -   5G 5th generation mobile networks    -   5GC 5G Core Network    -   5GS 5G System    -   5G-AN 5G Access Network    -   5QI 5G QoS Indicator    -   AF Application Function    -   AMF Access and Mobility Management Function    -   AN Access Network    -   CAG Closed Access Group    -   CDR Charging Data Record    -   CCNF Common Control Network Functions    -   CIoT Cellular IoT    -   CN Core Network    -   CP Control Plane    -   DDN Downlink Data Notification    -   DL Downlink    -   DN Data Network    -   DNN Data Network Name    -   F-TEID Fully Qualified TEID    -   GPSI Generic Public Subscription Identifier    -   GTP GPRS Tunneling Protocol    -   GUTI Globally Unique Temporary Identifier    -   HFN Hyper Frame Number    -   HO Handover    -   IMSI International Mobile Subscriber Identity    -   LADN Local Area Data Network    -   LI Lawful Intercept    -   MEI Mobile Equipment Identifier    -   MICO Mobile Initiated Connection Only    -   MME Mobility Management Entity    -   MO Mobile Originated    -   MSISDN Mobile Subscriber ISDN    -   MT Mobile Terminating    -   N3IWF Non-3GPP InterWorking Function    -   NAI Network Access Identifier    -   NAS Non-Access Stratum    -   NB-IoT Narrow Band IoT    -   NEF Network Exposure Function    -   NF Network Function    -   NGAP Next Generation Application Protocol    -   NR New Radio    -   NRF Network Repository Function    -   NPN Non Public Network    -   NSI Network Slice Instance    -   NSSAI Network Slice Selection Assistance Information    -   NSSF Network Slice Selection Function    -   OCS Online Charging System    -   OFCS Offline Charging System    -   PCF Policy Control Function    -   PDCP Packet Data Convergence Protocol    -   PDU Packet/Protocol Data Unit    -   PEI Permanent Equipment Identifier    -   PLMN Public Land Mobile Network    -   RAN Radio Access Network    -   RLC-AM Radio Link Control Acknowledge mode    -   QFI QoS Flow Identity    -   RM Registration Management    -   RRM Radio Resource Management    -   S1-AP S1 Application Protocol    -   SBA Service Based Architecture    -   SEA Security Anchor Function    -   SCM Security Context Management    -   SMF Session Management Function    -   SMSF SMS Function    -   S-NSSAI Single Network Slice Selection Assistance information    -   SSB Synchronization Signal Block    -   SUCI Served User Correlation ID    -   SUPI Subscriber Permanent Identifier    -   TA Tracking Area    -   TEID Tunnel Endpoint Identifier    -   TSN Time Sensitive Networking    -   UE User Equipment    -   UL Uplink    -   UL CL Uplink Classifier    -   UPF User Plane Function

Example FIG. 1 and FIG. 2 depict a 5G system comprising of accessnetworks and a 5G core network. An example 5G access network maycomprise an access network connecting to a 5G core network. An accessnetwork may comprise an NG-RAN 105 and/or non-3GPP AN 165. An example 5Gcore network may connect to one or more 5G access networks 5G-AN and/orNG-RANs. 5G core network may comprise functional elements or networkfunctions as in example FIG. 1 and example FIG. 2 where interfaces maybe employed for communication among the functional elements and/ornetwork elements.

In an example, a network function may be a processing function in anetwork, which may have a functional behavior and/or interfaces. Anetwork function may be implemented either as a network element on adedicated hardware, and/or a network node as depicted in FIG. 3 and FIG.4, or as a software instance running on a dedicated hardware and/orshared hardware, or as a virtualized function instantiated on anappropriate platform.

In an example, access and mobility management function, AMF 155, mayinclude the following functionalities (some of the AMF 155functionalities may be supported in a single instance of an AMF 155):termination of RAN 105 CP interface (N2), termination of NAS (N1), NASciphering and integrity protection, registration management, connectionmanagement, reachability management, mobility management, lawfulintercept (for AMF 155 events and interface to LI system), providetransport for session management, SM messages between UE 100 and SMF160, transparent proxy for routing SM messages, access authentication,access authorization, provide transport for SMS messages between UE 100and SMSF, security anchor function, SEA, interaction with the AUSF 150and the UE 100, receiving the intermediate key established as a resultof the UE 100 authentication process, security context management, SCM,that receives a key from the SEA that it uses to derive access networkspecific keys, and/or the like.

In an example, the AMF 155 may support non-3GPP access networks throughN2 interface with N3IWF 170, NAS signaling with a UE 100 over N3IWF 170,authentication of UEs connected over N3IWF 170, management of mobility,authentication, and separate security context state(s) of a UE 100connected via non-3GPP access 165 or connected via 3GPP access 105 andnon-3GPP access 165 simultaneously, support of a coordinated RM contextvalid over 3GPP access 105 and non 3GPP access 165, support of CMmanagement contexts for the UE 100 for connectivity over non-3GPPaccess, and/or the like.

In an example, an AMF 155 region may comprise one or multiple AMF 155sets. The AMF 155 set may comprise some AMF 155 that serve a given areaand/or network slice(s). In an example, multiple AMF 155 sets may be perAMF 155 region and/or network slice(s). Application identifier may be anidentifier that may be mapped to a specific application trafficdetection rule. Configured NSSAI may be an NSSAI that may be provisionedin a UE 100. DN 115 access identifier (DNAI), for a DNN, may be anidentifier of a user plane access to a DN 115. Initial registration maybe related to a UE 100 registration in RM-DEREGISTERED 500, 520 states.N2AP UE 100 association may be a logical per UE 100 association betweena 5G AN node and an AMF 155. N2AP UE-TNLA-binding may be a bindingbetween a N2AP UE 100 association and a specific transport networklayer, TNL association for a given UE 100.

In an example, session management function, SMF 160, may include one ormore of the following functionalities (one or more of the SMF 160functionalities may be supported in a single instance of a SMF 160):session management (e.g. session establishment, modify and release,including tunnel maintain between UPF 110 and AN 105 node), UE 100 IPaddress allocation & management (including optional authorization),selection and control of UP function(s), configuration of trafficsteering at UPF 110 to route traffic to proper destination, terminationof interfaces towards policy control functions, control part of policyenforcement and QoS. lawful intercept (for SM events and interface to LISystem), termination of SM parts of NAS messages, downlink datanotification, initiation of AN specific SM information, sent via AMF 155over N2 to (R)AN 105, determination of SSC mode of a session, roamingfunctionality, handling local enforcement to apply QoS SLAs (VPLMN),charging data collection and charging interface (VPLMN), lawfulintercept (in VPLMN for SM events and interface to LI System), supportfor interaction with external DN 115 for transport of signaling for PDUsession authorization/authentication by external DN 115, and/or thelike.

In an example, a user plane function, UPF 110, may include one or moreof the following functionalities (some of the UPF 110 functionalitiesmay be supported in a single instance of a UPF 110): anchor point forIntra-/Inter-RAT mobility (when applicable), external PDU session pointof interconnect to DN 115, packet routing & forwarding, packetinspection and user plane part of policy rule enforcement, lawfulintercept (UP collection), traffic usage reporting, uplink classifier tosupport routing traffic flows to a data network, branching point tosupport multi-homed PDU session(s), QoS handling for user plane, uplinktraffic verification (SDF to QoS flow mapping), transport level packetmarking in the uplink and downlink, downlink packet buffering, downlinkdata notification triggering, and/or the like.

In an example, the UE 100 IP address management may include allocationand release of the UE 100 IP address and/or renewal of the allocated IPaddress. The UE 100 may set a requested PDU type during a PDU sessionestablishment procedure based on its IP stack capabilities and/orconfiguration. In an example, the SMF 160 may select PDU type of a PDUsession. In an example, if the SMF 160 receives a request with PDU typeset to IP, the SMF 160 may select PDU type IPv4 or IPv6 based on DNNconfiguration and/or operator policies. In an example, the SMF 160 mayprovide a cause value to the UE 100 to indicate whether the other IPversion is supported on the DNN. In an example, if the SMF 160 receivesa request for PDU type IPv4 or IPv6 and the requested IP version issupported by the DNN the SMF 160 may select the requested PDU type.

In an example embodiment, the 5GC elements and UE 100 may support thefollowing mechanisms: during a PDU session establishment procedure, theSMF 160 may send the IP address to the UE 100 via SM NAS signaling. TheIPv4 address allocation and/or IPv4 parameter configuration via DHCPv4may be employed once PDU session may be established. IPv6 prefixallocation may be supported via IPv6 stateless autoconfiguration, ifIPv6 is supported. In an example, 5GC network elements may support IPv6parameter configuration via stateless DHCPv6.

The 5GC may support the allocation of a static IPv4 address and/or astatic IPv6 prefix based on subscription information in a UDM 140 and/orbased on the configuration on a per-subscriber, per-DNN basis.

User plane function(s) (UPF 110) may handle the user plane path of PDUsessions. A UPF 110 that provides the interface to a data network maysupport functionality of a PDU session anchor.

In an example, a policy control function, PCF 135, may support unifiedpolicy framework to govern network behavior, provide policy rules tocontrol plane function(s) to enforce policy rules, implement a front endto access subscription information relevant for policy decisions in auser data repository (UDR), and/or the like.

A network exposure function, NEF 125, may provide means to securelyexpose the services and capabilities provided by the 3GPP networkfunctions, translate between information exchanged with the AF 145 andinformation exchanged with the internal network functions, receiveinformation from other network functions, and/or the like.

In an example, a network repository function, NRF 130 may supportservice discovery function that may receive NF discovery request from NFinstance, provide information about the discovered NF instances (bediscovered) to the NF instance, and maintain information about availableNF instances and their supported services, and/or the like.

In an example, an NSSF 120 may select a set of network slice instancesserving the UE 100, may determine allowed NSSAI. In an example, the NSSF120 may determine the AMF 155 set to be employed to serve the UE 100,and/or, based on configuration, determine a list of candidate AMF 155(s)155 by querying the NRF 130.

In an example, stored data in a UDR may include at least usersubscription data, including at least subscription identifiers, securitycredentials, access and mobility related subscription data, sessionrelated subscription data, policy data, and/or the like.

In an example, an AUSF 150 may support authentication server function(AUSF 150).

In an example, an application function, AF 145, may interact with the3GPP core network to provide services. In an example, based on operatordeployment, application functions may be trusted by the operator tointeract directly with relevant network functions. Application functionsnot allowed by the operator to access directly the network functions mayuse an external exposure framework (e.g., via the NEF 125) to interactwith relevant network functions.

In an example, control plane interface between the (R)AN 105 and the 5Gcore may support connection of multiple different kinds of AN(s) (e.g.3GPP RAN 105, N3IWF 170 for Un-trusted access 165) to the 5GC via acontrol plane protocol. In an example, an N2 AP protocol may be employedfor both the 3GPP access 105 and non-3GPP access 165. In an example,control plane interface between the (R)AN 105 and the 5G core maysupport decoupling between AMF 155 and other functions such as SMF 160that may need to control the services supported by AN(s) (e.g. controlof the UP resources in the AN 105 for a PDU session).

In an example, the 5GC may provide policy information from the PCF 135to the UE 100. In an example, the policy information may comprise:access network discovery and selection policy, UE 100 route selectionpolicy (URSP), SSC mode selection policy (SSCMSP), network sliceselection policy (NSSP), DNN selection policy, non-seamless offloadpolicy, and/or the like.

In an example, as depicted in example FIG. 5A and FIG. 5B, theregistration management, RM may be employed to register or de-register aUE/user 100 with the network, and establish the user context in thenetwork. Connection management may be employed to establish and releasethe signaling connection between the UE 100 and the AMF 155.

In an example, a UE 100 may register with the network to receiveservices that require registration. In an example, the UE 100 may updateits registration with the network periodically in order to remainreachable (periodic registration update), or upon mobility (e.g.,mobility registration update), or to update its capabilities or tore-negotiate protocol parameters.

In an example, an initial registration procedure as depicted in exampleFIG. 8 and FIG. 9 may involve execution of network access controlfunctions (e.g. user authentication and access authorization based onsubscription profiles in UDM 140). Example FIG. 9 is a continuation ofthe initial registration procedure depicted in FIG. 8. As a result ofthe initial registration procedure, the identity of the serving AMF 155may be registered in a UDM 140.

In an example, the registration management, RM procedures may beapplicable over both 3GPP access 105 and non 3GPP access 165.

An example FIG. 5A may depict the RM states of a UE 100 as observed bythe UE 100 and AMF 155. In an example embodiment, two RM states may beemployed in the UE 100 and the AMF 155 that may reflect the registrationstatus of the UE 100 in the selected PLMN: RM-DEREGISTERED 500, andRM-REGISTERED 510. In an example, in the RM DEREGISTERED state 500, theUE 100 may not be registered with the network. The UE 100 context in theAMF 155 may not hold valid location or routing information for the UE100 so the UE 100 may not be reachable by the AMF 155. In an example,the UE 100 context may be stored in the UE 100 and the AMF 155. In anexample, in the RM REGISTERED state 510, the UE 100 may be registeredwith the network. In the RM-REGISTERED 510 state, the UE 100 may receiveservices that may require registration with the network.

In an example embodiment, two RM states may be employed in AMF 155 forthe UE 100 that may reflect the registration status of the UE 100 in theselected PLMN: RM-DEREGISTERED 520, and RM-REGISTERED 530.

As depicted in example FIG. 6A and FIG. 6B, connection management, CM,may comprise establishing and releasing a signaling connection between aUE 100 and an AMF 155 over N1 interface. The signaling connection may beemployed to enable NAS signaling exchange between the UE 100 and thecore network. The signaling connection between the UE 100 and the AMF155 may comprise both the AN signaling connection between the UE 100 andthe (R)AN 105 (e.g. RRC connection over 3GPP access) and the N2connection for the UE 100 between the AN and the AMF 155.

As depicted in example FIG. 6A and FIG. 6B, two CM states may beemployed for the NAS signaling connectivity of the UE 100 with the AMF155, CM-IDLE 600, 620 and CM-CONNECTED 610, 630. A UE 100 in CM-IDLE 600state may be in RM-REGISTERED 510 state and may have no NAS signalingconnection established with the AMF 155 over N1. The UE 100 may performcell selection, cell reselection, PLMN selection, and/or the like. A UE100 in CM-CONNECTED 610 state may have a NAS signaling connection withthe AMF 155 over N1.

In an example embodiment two CM states may be employed for the UE 100 atthe AMF 155, CM-IDLE 620 and CM-CONNECTED 630.

In an example, an RRC inactive state may apply to NG-RAN (e.g. it mayapply to NR and E-UTRA connected to 5G CN). The AMF 155, based onnetwork configuration, may provide assistance information to the NG RAN105, to assist the NG RAN's 105 decision whether the UE 100 may be sentto RRC inactive state. When a UE 100 is CM-CONNECTED 610 with RRCinactive state, the UE 100 may resume the RRC connection due to uplinkdata pending, mobile initiated signaling procedure, as a response to RAN105 paging, to notify the network that it has left the RAN 105notification area, and/or the like.

In an example, a NAS signaling connection management may includeestablishing and releasing a NAS signaling connection. A NAS signalingconnection establishment function may be provided by the UE 100 and theAMF 155 to establish the NAS signaling connection for the UE 100 inCM-IDLE 600 state. The procedure of releasing the NAS signalingconnection may be initiated by the 5G (R)AN 105 node or the AMF 155.

In an example, reachability management of a UE 100 may detect whetherthe UE 100 is reachable and may provide the UE 100 location (e.g. accessnode) to the network to reach the UE 100. Reachability management may bedone by paging the UE 100 and the UE 100 location tracking. The UE 100location tracking may include both UE 100 registration area tracking andUE 100 reachability tracking. The UE 100 and the AMF 155 may negotiateUE 100 reachability characteristics in CM-IDLE 600, 620 state duringregistration and registration update procedures.

In an example, two UE 100 reachability categories may be negotiatedbetween a UE 100 and an AMF 155 for CM-IDLE 600, 620 state. 1) UE 100reachability allowing mobile device terminated data while the UE 100 isCM-IDLE 600 mode. 2) Mobile initiated connection only (MICO) mode. The5GC may support a PDU connectivity service that provides exchange ofPDUs between the UE 100 and a data network identified by a DNN. The PDUconnectivity service may be supported via PDU sessions that areestablished upon request from the UE 100.

In an example, a PDU session may support one or more PDU session types.PDU sessions may be established (e.g. upon UE 100 request), modified(e.g. upon UE 100 and 5GC request) and/or released (e.g. upon UE 100 and5GC request) using NAS SM signaling exchanged over N1 between the UE 100and the SMF 160. Upon request from an application server, the 5GC may beable to trigger a specific application in the UE 100. When receiving thetrigger, the UE 100 may send it to the identified application in the UE100. The identified application in the UE 100 may establish a PDUsession to a specific DNN.

In an example, the 5G QoS model may support a QoS flow based frameworkas depicted in example FIG. 7. The 5G QoS model may support both QoSflows that require a guaranteed flow bit rate and QoS flows that may notrequire a guaranteed flow bit rate. In an example, the 5G QoS model maysupport reflective QoS. The QoS model may comprise flow mapping orpacket marking at the UPF 110 (CN_UP) 110, AN 105 and/or the UE 100. Inan example, packets may arrive from and/or destined to theapplication/service layer 730 of UE 100, UPF 110 (CN_UP) 110, and/or theAF 145.

In an example, the QoS flow may be a granularity of QoS differentiationin a PDU session. A QoS flow ID, QFI, may be employed to identify theQoS flow in the 5G system. In an example, user plane traffic with thesame QFI within a PDU session may receive the same traffic forwardingtreatment. The QFI may be carried in an encapsulation header on N3and/or N9 (e.g. without any changes to the end-to-end packet header). Inan example, the QFI may be applied to PDUs with different types ofpayload. The QFI may be unique within a PDU session.

In an example, the QoS parameters of a QoS flow may be provided to the(R)AN 105 as a QoS profile over N2 at PDU session establishment, QoSflow establishment, or when NG-RAN is used at every time the user planeis activated. In an example, a default QoS rule may be required forevery PDU session. The SMF 160 may allocate the QFI for a QoS flow andmay derive QoS parameters from the information provided by the PCF 135.In an example, the SMF 160 may provide the QFI together with the QoSprofile containing the QoS parameters of a QoS flow to the (R)AN 105.

In an example, 5G QoS flow may be a granularity for QoS forwardingtreatment in the 5G system. Traffic mapped to the same 5G QoS flow mayreceive the same forwarding treatment (e.g. scheduling policy, queuemanagement policy, rate shaping policy, RLC configuration, and/or thelike). In an example, providing different QoS forwarding treatment mayrequire separate 5G QoS flows.

In an example, a 5G QoS indicator may be a scalar that may be employedas a reference to a specific QoS forwarding behavior (e.g. packet lossrate, packet delay budget) to be provided to a 5G QoS flow. In anexample, the 5G QoS indicator may be implemented in the access networkby the 5QI referencing node specific parameters that may control the QoSforwarding treatment (e.g. scheduling weights, admission thresholds,queue management thresholds, link layer protocol configuration, and/orthe like).

In an example, 5GC may support edge computing and may enable operator(s)and 3rd party services to be hosted close to the UE's access point ofattachment. The 5G core network may select a UPF 110 close to the UE 100and may execute the traffic steering from the UPF 110 to the local datanetwork via a N6 interface. In an example, the selection and trafficsteering may be based on the UE's 100 subscription data, UE 100location, the information from application function AF 145, policy,other related traffic rules, and/or the like. In an example, the 5G corenetwork may expose network information and capabilities to an edgecomputing application function. The functionality support for edgecomputing may include local routing where the 5G core network may selecta UPF 110 to route the user traffic to the local data network, trafficsteering where the 5G core network may select the traffic to be routedto the applications in the local data network, session and servicecontinuity to enable UE 100 and application mobility, user planeselection and reselection, e.g. based on input from applicationfunction, network capability exposure where 5G core network andapplication function may provide information to each other via NEF 125,QoS and charging where PCF 135 may provide rules for QoS control andcharging for the traffic routed to the local data network, support oflocal area data network where 5G core network may provide support toconnect to the LADN in a certain area where the applications aredeployed, and/or the like.

An example 5G system may be a 3GPP system comprising of 5G accessnetwork 105, 5G core network and a UE 100, and/or the like. AllowedNSSAI may be an NSSAI provided by a serving PLMN during e.g. aregistration procedure, indicating the NSSAI allowed by the network forthe UE 100 in the serving PLMN for the current registration area.

In an example, a PDU connectivity service may provide exchange of PDUsbetween a UE 100 and a data network. A PDU session may be an associationbetween the UE 100 and the data network, DN 115, that may provide thePDU connectivity service. The type of association may be IP, Ethernetand/or unstructured.

Establishment of user plane connectivity to a data network via networkslice instance(s) may comprise the following: performing a RM procedureto select an AMF 155 that supports the required network slices, andestablishing one or more PDU session(s) to the required data network viathe network slice instance(s).

In an example, the set of network slices for a UE 100 may be changed atany time while the UE 100 may be registered with the network, and may beinitiated by the network, or the UE 100.

In an example, a periodic registration update may be UE 100re-registration at expiry of a periodic registration timer. A requestedNSSAI may be a NSSAI that the UE 100 may provide to the network.

In an example, a service based interface may represent how a set ofservices may be provided/exposed by a given NF.

In an example, a service continuity may be an uninterrupted userexperience of a service, including the cases where the IP address and/oranchoring point may change. In an example, a session continuity mayrefer to continuity of a PDU session. For PDU session of IP type sessioncontinuity may imply that the IP address is preserved for the lifetimeof the PDU session. An uplink classifier may be a UPF 110 functionalitythat aims at diverting uplink traffic, based on filter rules provided bythe SMF 160, towards data network, DN 115.

In an example, the 5G system architecture may support data connectivityand services enabling deployments to use techniques such as e.g. networkfunction virtualization and/or software defined networking. The 5Gsystem architecture may leverage service-based interactions betweencontrol plane (CP) network functions where identified. In 5G systemarchitecture, separation of the user plane (UP) functions from thecontrol plane functions may be considered. A 5G system may enable anetwork function to interact with other NF(s) directly if required.

In an example, the 5G system may reduce dependencies between the accessnetwork (AN) and the core network (CN). The architecture may comprise aconverged access-agnostic core network with a common AN CN interfacewhich may integrate different 3GPP and non-3GPP access types.

In an example, the 5G system may support a unified authenticationframework, stateless NFs, where the compute resource is decoupled fromthe storage resource, capability exposure, and concurrent access tolocal and centralized services. To support low latency services andaccess to local data networks, UP functions may be deployed close to theaccess network.

In an example, the 5G system may support roaming with home routedtraffic and/or local breakout traffic in the visited PLMN. An example 5Garchitecture may be service-based and the interaction between networkfunctions may be represented in two ways. (1) As service-basedrepresentation (depicted in example FIG. 1), where network functionswithin the control plane, may enable other authorized network functionsto access their services. This representation may also includepoint-to-point reference points where necessary. (2) Reference pointrepresentation, showing the interaction between the NF services in thenetwork functions described by point-to-point reference point (e.g. N11)between any two network functions.

In an example, a network slice may comprise the core network controlplane and user plane network functions, the 5G Radio Access Network; theN3IWF functions to the non-3GPP Access Network, and/or the like. Networkslices may differ for supported features and network functionimplementation. The operator may deploy multiple network slice instancesdelivering the same features but for different groups of UEs, e.g. asthey deliver a different committed service and/or because they may bededicated to a customer. The NSSF 120 may store the mapping informationbetween slice instance ID and NF ID (or NF address).

In an example, a UE 100 may simultaneously be served by one or morenetwork slice instances via a 5G-AN. In an example, the UE 100 may beserved by k network slices (e.g. k=8, 16, etc) at a time. An AMF 155instance serving the UE 100 logically may belong to a network sliceinstance serving the UE 100.

In an example, a PDU session may belong to one specific network sliceinstance per PLMN. In an example, different network slice instances maynot share a PDU session. Different slices may have slice-specific PDUsessions using the same DNN.

An S-NSSAI (Single Network Slice Selection Assistance information) mayidentify a network slice. An S-NSSAI may comprise a slice/service type(SST), which may refer to the expected network slice behavior in termsof features and services; and/or a slice differentiator (SD). A slicedifferentiator may be optional information that may complement theslice/service type(s) to allow further differentiation for selecting anetwork slice instance from potentially multiple network slice instancesthat comply with the indicated slice/service type. In an example, thesame network slice instance may be selected employing differentS-NSSAIs. The CN part of a network slice instance(s) serving a UE 100may be selected by CN.

In an example, subscription data may include the S-NSSAI(s) of thenetwork slices that the UE 100 subscribes to. One or more S-NSSAIs maybe marked as default S-NSSAI. In an example, k S-NSSAI may be markeddefault S-NSSAI (e.g. k=8, 16, etc.). In an example, the UE 100 maysubscribe to more than 8 S-NSSAIs.

In an example, a UE 100 may be configured by the HPLMN with a configuredNSSAI per PLMN. Upon successful completion of a UE's registrationprocedure, the UE 100 may obtain from the AMF 155 an Allowed NSSAI forthis PLMN, which may include one or more S-NSSAIs.

In an example, the Allowed NSSAI may take precedence over the configuredNSSAI for a PLMN. The UE 100 may use the S-NSSAIs in the allowed NSSAIcorresponding to a network slice for the subsequent network sliceselection related procedures in the serving PLMN.

In an example, the establishment of user plane connectivity to a datanetwork via a network slice instance(s) may comprise: performing a RMprocedure to select an AMF 155 that may support the required networkslices, establishing one or more PDU sessions to the required datanetwork via the network slice instance(s), and/or the like.

In an example, when a UE 100 registers with a PLMN, if the UE 100 forthe PLMN has a configured NSSAI or an allowed NSSAI, the UE 100 mayprovide to the network in RRC and NAS layer a requested NSSAI comprisingthe S-NSSAI(s) corresponding to the slice(s) to which the UE 100attempts to register, a temporary user ID if one was assigned to the UE,and/or the like. The requested NSSAI may be configured-NSSAI,allowed-NSSAI, and/or the like.

In an example, when a UE 100 registers with a PLMN, if for the PLMN theUE 100 has no configured NSSAI or allowed NSSAI, the RAN 105 may routeNAS signaling from/to the UE 100 to/from a default AMF 155.

In an example, the network, based on local policies, subscriptionchanges and/or UE 100 mobility, may change the set of permitted networkslice(s) to which the UE 100 is registered. In an example, the networkmay perform the change during a registration procedure or trigger anotification towards the UE 100 of the change of the supported networkslices using an RM procedure (which may trigger a registrationprocedure). The network may provide the UE 100 with a new allowed NSSAIand tracking area list.

In an example, during a registration procedure in a PLMN, in case thenetwork decides that the UE 100 may be served by a different AMF 155based on network slice(s) aspects, the AMF 155 that first received theregistration request may redirect the registration request to anotherAMF 155 via the RAN 105 or via direct signaling between the initial AMF155 and the target AMF 155.

In an example, the network operator may provision the UE 100 withnetwork slice selection policy (NSSP). The NSSP may comprise one or moreNSSP rules.

In an example, if a UE 100 has one or more PDU sessions establishedcorresponding to a specific S-NSSAI, the UE 100 may route the user dataof the application in one of the PDU sessions, unless other conditionsin the UE 100 may prohibit the use of the PDU sessions. If theapplication provides a DNN, then the UE 100 may consider the DNN todetermine which PDU session to use. In an example, if the UE 100 doesnot have a PDU session established with the specific S-NSSAI, the UE 100may request a new PDU session corresponding to the S-NSSAI and with theDNN that may be provided by the application. In an example, in order forthe RAN 105 to select a proper resource for supporting network slicingin the RAN 105, the RAN 105 may be aware of the network slices used bythe UE 100.

In an example, an AMF 155 may select an SMF 160 in a network sliceinstance based on S-NSSAI, DNN and/or other information e.g. UE 100subscription and local operator policies, and/or the like, when the UE100 triggers the establishment of a PDU session. The selected SMF 160may establish the PDU session based on S-NSSAI and DNN.

In an example, in order to support network-controlled privacy of sliceinformation for the slices the UE 100 may access, when the UE 100 isaware or configured that privacy considerations may apply to NSSAI, theUE 100 may not include NSSAI in NAS signaling unless the UE 100 has aNAS security context and the UE 100 may not include NSSAI in unprotectedRRC signaling.

In an example, for roaming scenarios, the network slice specific networkfunctions in VPLMN and HPLMN may be selected based on the S-NSSAIprovided by the UE 100 during PDU connection establishment. If astandardized S-NSSAI is used, selection of slice specific NF instancesmay be done by one or more PLMN(s) based on the provided S-NSSAI. In anexample, the VPLMN may map the S-NSSAI of HPLMN to a S-NSSAI of VPLMNbased on roaming agreement (e.g., including mapping to a default S-NSSAIof VPLMN). In an example, the selection of slice specific NF instance inVPLMN may be done based on the S-NSSAI of VPLMN. In an example, theselection of any slice specific NF instance in HPLMN may be based on theS-NSSAI of HPLMN.

As depicted in example FIG. 8 and FIG. 9, a registration procedure maybe performed by the UE 100 to get authorized to receive services, toenable mobility tracking, to enable reachability, and/or the like.

In an example, the UE 100 may send to the (R)AN 105 an AN message 805(comprising AN parameters, RM-NAS registration request (registrationtype, SUCI or SUPI or 5G-GUTI, last visited TAI (if available), securityparameters, requested NSSAI, mapping of requested NSSAI, UE 100 5GCcapability, PDU session status, PDU session(s) to be re-activated,Follow on request, MICO mode preference, and/or the like), and/or thelike). In an example, in case of NG-RAN, the AN parameters may includee.g. SUCI or SUPI or the 5G-GUTI, the Selected PLMN ID and requestedNSSAI, and/or the like. In an example, the AN parameters may compriseestablishment cause. The establishment cause may provide the reason forrequesting the establishment of an RRC connection. In an example, theregistration type may indicate if the UE 100 wants to perform an initialregistration (i.e. the UE 100 is in RM-DEREGISTERED state), a mobilityregistration update (e.g., the UE 100 is in RM-REGISTERED state andinitiates a registration procedure due to mobility), a periodicregistration update (e.g., the UE 100 is in RM-REGISTERED state and mayinitiate a registration procedure due to the periodic registrationupdate timer expiry) or an emergency registration (e.g., the UE 100 isin limited service state). In an example, if the UE 100 performing aninitial registration (i.e., the UE 100 is in RM-DEREGISTERED state) to aPLMN for which the UE 100 does not already have a 5G-GUTI, the UE 100may include its SUCI or SUPI in the registration request. The SUCI maybe included if the home network has provisioned the public key toprotect SUPI in the UE. If the UE 100 received a UE 100 configurationupdate command indicating that the UE 100 needs to re-register and the5G-GUTI is invalid, the UE 100 may perform an initial registration andmay include the SUPI in the registration request message. For anemergency registration, the SUPI may be included if the UE 100 does nothave a valid 5G-GUTI available; the PEI may be included when the UE 100has no SUPI and no valid 5G-GUTI. In other cases, the 5G-GUTI may beincluded and it may indicate the last serving AMF 155. If the UE 100 isalready registered via a non-3GPP access in a PLMN different from thenew PLMN (e.g., not the registered PLMN or an equivalent PLMN of theregistered PLMN) of the 3GPP access, the UE 100 may not provide over the3GPP access the 5G-GUTI allocated by the AMF 155 during the registrationprocedure over the non-3GPP access. If the UE 100 is already registeredvia a 3GPP access in a PLMN (e.g., the registered PLMN), different fromthe new PLMN (i.e. not the registered PLMN or an equivalent PLMN of theregistered PLMN) of the non-3GPP access, the UE 100 may not provide overthe non-3GPP access the 5G-GUTI allocated by the AMF 155 during theregistration procedure over the 3GPP access. The UE 100 may provide theUE's usage setting based on its configuration. In case of initialregistration or mobility registration update, the UE 100 may include themapping of requested NSSAI, which may be the mapping of one or moreS-NSSAI of the requested NSSAI to the S-NSSAIs of the configured NSSAIfor the HPLMN, to ensure that the network is able to verify whether theS-NSSAI(s) in the requested NSSAI are permitted based on the subscribedS-NSSAIs. If available, the last visited TAI may be included in order tohelp the AMF 155 produce registration area for the UE. In an example,the security parameters may be used for authentication and integrityprotection. requested NSSAI may indicate the network slice selectionassistance information. The PDU session status may indicates thepreviously established PDU sessions in the UE. When the UE 100 isconnected to the two AMF 155 belonging to different PLMN via 3GPP accessand non-3GPP access then the PDU session status may indicate theestablished PDU session of the current PLMN in the UE. The PDUsession(s) to be re-activated may be included to indicate the PDUsession(s) for which the UE 100 may intend to activate UP connections. APDU session corresponding to a LADN may not be included in the PDUsession(s) to be re-activated when the UE 100 is outside the area ofavailability of the LADN. The follow on request may be included when theUE 100 may have pending uplink signaling and the UE 100 may not includePDU session(s) to be re-activated, or the registration type may indicatethe UE 100 may want to perform an emergency registration.

In an example, if a SUPI is included or the 5G-GUTI does not indicate avalid AMF 155, the (R)AN 105, based on (R)AT and requested NSSAI, ifavailable, may selects 808 an AMF 155. If UE 100 is in CM-CONNECTEDstate, the (R)AN 105 may forward the registration request message to theAMF 155 based on the N2 connection of the UE. If the (R)AN 105 may notselect an appropriate AMF 155, it may forward the registration requestto an AMF 155 which has been configured, in (R)AN 105, to perform AMF155 selection 808.

In an example, the (R)AN 105 may send to the new AMF 155 an N2 message810 (comprising: N2 parameters, RM-NAS registration request(registration type, SUPI or 5G-GUTI, last visited TAI (if available),security parameters, requested NSSAI, mapping of requested NSSAI, UE 1005GC capability, PDU session status, PDU session(s) to be re-activated,follow on request, and MICO mode preference), and/or the like). In anexample, when NG-RAN is used, the N2 parameters may comprise theselected PLMN ID, location information, cell identity and the RAT typerelated to the cell in which the UE 100 is camping. In an example, whenNG-RAN is used, the N2 parameters may include the establishment cause.

In an example, the new AMF 155 may send to the old AMF 155 anNamf_Communication_UEContextTransfer (complete registration request)815. In an example, if the UE's 5G-GUTI was included in the registrationrequest and the serving AMF 155 has changed since last registrationprocedure, the new AMF 155 may invoke theNamf_Communication_UEContextTransfer service operation 815 on the oldAMF 155 including the complete registration request IE, which may beintegrity protected, to request the UE's SUPI and MM Context. The oldAMF 155 may use the integrity protected complete registration request IEto verify if the context transfer service operation invocationcorresponds to the UE 100 requested. In an example, the old AMF 155 maytransfer the event subscriptions information by one or more NF consumer,for the UE, to the new AMF 155. In an example, if the UE 100 identifiesitself with PEI, the SUPI request may be skipped.

In an example, the old AMF 155 may send to new AMF 155 a response 815 toNamf_Communication_UEContextTransfer (SUPI, MM context, SMF 160information, PCF ID). In an example, the old AMF 155 may respond to thenew AMF 155 for the Namf_Communication_UEContextTransfer invocation byincluding the UE's SUPI and MM context. In an example, if old AMF 155holds information about established PDU sessions, the old AMF 155 mayinclude SMF 160 information including S-NSSAI(s), SMF 160 identities andPDU session ID. In an example, if old AMF 155 holds information aboutactive NGAP UE-TNLA bindings to N3IWF, the old AMF 155 may includeinformation about the NGAP UE-TNLA bindings.

In an example, if the SUPI is not provided by the UE 100 nor retrievedfrom the old AMF 155 the identity request procedure 820 may be initiatedby the AMF 155 sending an identity request message to the UE 100requesting the SUCI.

In an example, the UE 100 may respond with an identity response message820 including the SUCI. The UE 100 may derive the SUCI by using theprovisioned public key of the HPLMN.

In an example, the AMF 155 may decide to initiate UE 100 authentication825 by invoking an AUSF 150. The AMF 155 may select an AUSF 150 based onSUPI or SUCI. In an example, if the AMF 155 is configured to supportemergency registration for unauthenticated SUPIs and the UE 100indicated registration type emergency registration the AMF 155 may skipthe authentication and security setup or the AMF 155 may accept that theauthentication may fail and may continue the registration procedure.

In an example, the authentication 830 may be performed byNudm_UEAuthenticate_Get operation. The AUSF 150 may discover a UDM 140.In case the AMF 155 provided a SUCI to AUSF 150, the AUSF 150 may returnthe SUPI to AMF 155 after the authentication is successful. In anexample, if network slicing is used, the AMF 155 may decide if theregistration request needs to be rerouted where the initial AMF 155refers to the AMF 155. In an example, the AMF 155 may initiate NASsecurity functions. In an example, upon completion of NAS securityfunction setup, the AMF 155 may initiate NGAP procedure to enable 5G-ANuse it for securing procedures with the UE. In an example, the 5G-AN maystore the security context and may acknowledge to the AMF 155. The 5G-ANmay use the security context to protect the messages exchanged with theUE.

In an example, new AMF 155 may send to the old AMF 155Namf_Communication_RegistrationCompleteNotify 835. If the AMF 155 haschanged, the new AMF 155 may notify the old AMF 155 that theregistration of the UE 100 in the new AMF 155 may be completed byinvoking the Namf_Communication_RegistrationCompleteNotify serviceoperation. If the authentication/security procedure fails, then theregistration may be rejected, and the new AMF 155 may invoke theNamf_Communication_RegistrationCompleteNotify service operation with areject indication reason code towards the old AMF 155. The old AMF 155may continue as if the UE 100 context transfer service operation wasnever received. If one or more of the S-NSSAIs used in the oldregistration area may not be served in the target registration area, thenew AMF 155 may determine which PDU session may not be supported in thenew registration area. The new AMF 155 may invoke theNamf_Communication_RegistrationCompleteNotify service operationincluding the rejected PDU session ID and a reject cause (e.g. theS-NSSAI becomes no longer available) towards the old AMF 155. The newAMF 155 may modify the PDU session status correspondingly. The old AMF155 may inform the corresponding SMF 160(s) to locally release the UE'sSM context by invoking the Nsmf_PDUSession_ReleaseSMContext serviceoperation.

In an example, the new AMF 155 may send to the UE 100 an identityrequest/response 840 (e.g., PEI). If the PEI was not provided by the UE100 nor retrieved from the old AMF 155, the identity request proceduremay be initiated by AMF 155 sending an identity request message to theUE 100 to retrieve the PEI. The PEI may be transferred encrypted unlessthe UE 100 performs emergency registration and may not be authenticated.For an emergency registration, the UE 100 may have included the PEI inthe registration request.

In an example, the new AMF 155 may initiate ME identity check 845 byinvoking the N5g-eir_EquipmentIdentityCheck_Get service operation 845.

In an example, the new AMF 155, based on the SUPI, may select 905 a UDM140. The UDM 140 may select a UDR instance. In an example, the AMF 155may select a UDM 140.

In an example, if the AMF 155 has changed since the last registrationprocedure, or if the UE 100 provides a SUPI which may not refer to avalid context in the AMF 155, or if the UE 100 registers to the same AMF155 it has already registered to a non-3GPP access (e.g., the UE 100 isregistered over a non-3GPP access and may initiate the registrationprocedure to add a 3GPP access), the new AMF 155 may register with theUDM 140 using Nudm_UECM_Registration 910 and may subscribe to benotified when the UDM 140 may deregister the AMF 155. The UDM 140 maystore the AMF 155 identity associated to the access type and may notremove the AMF 155 identity associated to the other access type. The UDM140 may store information provided at registration in UDR, byNudr_UDM_Update. In an example, the AMF 155 may retrieve the access andmobility subscription data and SMF 160 selection subscription data usingNudm_SDM_Get 915. The UDM 140 may retrieve this information from UDR byNudr_UDM_Query (access and mobility subscription data). After asuccessful response is received, the AMF 155 may subscribe to benotified using Nudm_SDM_Subscribe 920 when the data requested may bemodified. The UDM 140 may subscribe to UDR by Nudr_UDM_Subscribe. TheGPSI may be provided to the AMF 155 in the subscription data from theUDM 140 if the GPSI is available in the UE 100 subscription data. In anexample, the new AMF 155 may provide the access type it serves for theUE 100 to the UDM 140 and the access type may be set to 3GPP access. TheUDM 140 may store the associated access type together with the servingAMF 155 in UDR by Nudr_UDM_Update. The new AMF 155 may create an MMcontext for the UE 100 after getting the mobility subscription data fromthe UDM 140. In an example, when the UDM 140 stores the associatedaccess type together with the serving AMF 155, the UDM 140 may initiatea Nudm_UECM_DeregistrationNotification 921 to the old AMF 155corresponding to 3GPP access. The old AMF 155 may remove the MM contextof the UE. If the serving NF removal reason indicated by the UDM 140 isinitial registration, then the old AMF 155 may invoke theNamf_EventExposure_Notify service operation towards all the associatedSMF 160 s of the UE 100 to notify that the UE 100 is deregistered fromold AMF 155. The SMF 160 may release the PDU session(s) on getting thisnotification. In an example, the old AMF 155 may unsubscribe with theUDM 140 for subscription data using Nudm_SDM_unsubscribe 922.

In an example, if the AMF 155 decides to initiate PCF 135 communication,e.g. the AMF 155 has not yet obtained access and mobility policy for theUE 100 or if the access and mobility policy in the AMF 155 are no longervalid, the AMF 155 may select 925 a PCF 135. If the new AMF 155 receivesa PCF ID from the old AMF 155 and successfully contacts the PCF 135identified by the PCF ID, the AMF 155 may select the (V)PCF identifiedby the PCF ID. If the PCF 135 identified by the PCF ID may not be used(e.g. no response from the PCF 135) or if there is no PCF ID receivedfrom the old AMF 155, the AMF 155 may select 925 a PCF 135.

In an example, the new AMF 155 may perform a policy associationestablishment 930 during registration procedure. If the new AMF 155contacts the PCF 135 identified by the (V)PCF ID received duringinter-AMF 155 mobility, the new AMF 155 may include the PCF-ID in theNpcf_AMPolicyControl Get operation. If the AMF 155 notifies the mobilityrestrictions (e.g. UE 100 location) to the PCF 135 for adjustment, or ifthe PCF 135 updates the mobility restrictions itself due to someconditions (e.g. application in use, time and date), the PCF 135 mayprovide the updated mobility restrictions to the AMF 155.

In an example, the PCF 135 may invoke Namf_EventExposure_Subscribeservice operation 935 for UE 100 event subscription.

In an example, the AMF 155 may send to the SMF 160 anNsmf_PDUSession_UpdateSMContext 936. In an example, the AMF 155 mayinvoke the Nsmf_PDUSession_UpdateSMContext if the PDU session(s) to bere-activated is included in the registration request. The AMF 155 maysend Nsmf_PDUSession_UpdateSMContext request to SMF 160(s) associatedwith the PDU session(s) to activate user plane connections of the PDUsession(s). The SMF 160 may decide to trigger e.g. the intermediate UPF110 insertion, removal or change of PSA. In the case that theintermediate UPF 110 insertion, removal, or relocation is performed forthe PDU session(s) not included in PDU session(s) to be re-activated,the procedure may be performed without N11 and N2 interactions to updatethe N3 user plane between (R)AN 105 and 5GC. The AMF 155 may invoke theNsmf_PDUSession_ReleaseSMContext service operation towards the SMF 160if any PDU session status indicates that it is released at the UE 100.The AMF 155 may invoke the Nsmf_PDUSession_ReleaseSMContext serviceoperation towards the SMF 160 in order to release any network resourcesrelated to the PDU session.

In an example, the new AMF 155155 may send to a N3IWF an N2 AMF 155mobility request 940. If the AMF 155 has changed, the new AMF 155 maycreate an NGAP UE 100 association towards the N3IWF to which the UE 100is connected. In an example, the N3IWF may respond to the new AMF 155with an N2 AMF 155 mobility response 940.

In an example, the new AMF 155 may send to the UE 100 a registrationaccept 955 (comprising: 5G-GUTI, registration area, mobilityrestrictions, PDU session status, allowed NSSAI, [mapping of allowedNSSAI], periodic registration update timer, LADN information andaccepted MICO mode, IMS voice over PS session supported indication,emergency service support indicator, and/or the like). In an example,the AMF 155 may send the registration accept message to the UE 100indicating that the registration request has been accepted. 5G-GUTI maybe included if the AMF 155 allocates a new 5G-GUTI. If the AMF 155allocates a new registration area, it may send the registration area tothe UE 100 via registration accept message 955. If there is noregistration area included in the registration accept message, the UE100 may consider the old registration area as valid. In an example,mobility restrictions may be included in case mobility restrictions mayapply for the UE 100 and registration type may not be emergencyregistration. The AMF 155 may indicate the established PDU sessions tothe UE 100 in the PDU session status. The UE 100 may remove locally anyinternal resources related to PDU sessions that are not marked asestablished in the received PDU session status. In an example, when theUE 100 is connected to the two AMF 155 belonging to different PLMN via3GPP access and non-3GPP access then the UE 100 may remove locally anyinternal resources related to the PDU session of the current PLMN thatare not marked as established in received PDU session status. If the PDUsession status information was in the registration request, the AMF 155may indicate the PDU session status to the UE. The mapping of allowedNSSAI may be the mapping of one or more S-NSSAI of the allowed NSSAI tothe S-NSSAIs of the configured NSSAI for the HPLMN. The AMF 155 mayinclude in the registration accept message 955 the LADN information forLADNs that are available within the registration area determined by theAMF 155 for the UE. If the UE 100 included MICO mode in the request,then AMF 155 may respond whether MICO mode may be used. The AMF 155 mayset the IMS voice over PS session supported Indication. In an example,in order to set the IMS voice over PS session supported indication, theAMF 155 may perform a UE/RAN radio information and compatibility requestprocedure to check the compatibility of the UE 100 and RAN radiocapabilities related to IMS voice over PS. In an example, the emergencyservice support indicator may inform the UE 100 that emergency servicesare supported, e.g., the UE 100 may request PDU session for emergencyservices. In an example, the handover restriction list and UE-AMBR maybe provided to NG-RAN by the AMF 155.

In an example, the UE 100 may send to the new AMF 155 a registrationcomplete 960 message. In an example, the UE 100 may send theregistration complete message 960 to the AMF 155 to acknowledge that anew 5G-GUTI may be assigned. In an example, when information about thePDU session(s) to be re-activated is not included in the registrationrequest, the AMF 155 may release the signaling connection with the UE100. In an example, when the follow-on request is included in theregistration request, the AMF 155 may not release the signalingconnection after the completion of the registration procedure. In anexample, if the AMF 155 is aware that some signaling is pending in theAMF 155 or between the UE 100 and the 5GC, the AMF 155 may not releasethe signaling connection after the completion of the registrationprocedure.

As depicted in example FIG. 10 and FIG. 11, a service request proceduree.g., a UE 100 triggered service request procedure may be used by a UE100 in CM-IDLE state to request the establishment of a secure connectionto an AMF 155. FIG. 11 is continuation of FIG. 10 depicting the servicerequest procedure. The service request procedure may be used to activatea user plane connection for an established PDU session. The servicerequest procedure may be triggered by the UE 100 or the 5GC, and may beused when the UE 100 is in CM-IDLE and/or in CM-CONNECTED and may allowselectively to activate user plane connections for some of theestablished PDU sessions.

In an example, a UE 100 in CM IDLE state may initiate the servicerequest procedure to send uplink signaling messages, user data, and/orthe like, as a response to a network paging request, and/or the like. Inan example, after receiving the service request message, the AMF 155 mayperform authentication. In an example, after the establishment ofsignaling connection to the AMF 155, the UE 100 or network may sendsignaling messages, e.g. PDU session establishment from the UE 100 to aSMF 160, via the AMF 155.

In an example, for any service request, the AMF 155 may respond with aservice accept message to synchronize PDU session status between the UE100 and network. The AMF 155 may respond with a service reject messageto the UE 100, if the service request may not be accepted by thenetwork. The service reject message may include an indication or causecode requesting the UE 100 to perform a registration update procedure.In an example, for service request due to user data, network may takefurther actions if user plane connection activation may not besuccessful. In an example FIG. 10 and FIG. 11, more than one UPF, e.g.,old UPF 110-2 and PDU session Anchor PSA UPF 110-3 may be involved.

In an example, the UE 100 may send to a (R)AN 105 an AN messagecomprising AN parameters, mobility management, MM NAS service request1005 (e.g., list of PDU sessions to be activated, list of allowed PDUsessions, security parameters, PDU session status, and/or the like),and/or the like. In an example, the UE 100 may provide the list of PDUsessions to be activated when the UE 100 may re-activate the PDUsession(s). The list of allowed PDU sessions may be provided by the UE100 when the service request may be a response of a paging or a NASnotification, and may identify the PDU sessions that may be transferredor associated to the access on which the service request may be sent. Inan example, for the case of NG-RAN, the AN parameters may includeselected PLMN ID, and an establishment cause. The establishment causemay provide the reason for requesting the establishment of an RRCconnection. The UE 100 may send NAS service request message towards theAMF 155 encapsulated in an RRC message to the RAN 105.

In an example, if the service request may be triggered for user data,the UE 100 may identify, using the list of PDU sessions to be activated,the PDU session(s) for which the UP connections are to be activated inthe NAS service request message. If the service request may be triggeredfor signaling, the UE 100 may not identify any PDU session(s). If thisprocedure may be triggered for paging response, and/or the UE 100 mayhave at the same time user data to be transferred, the UE 100 mayidentify the PDU session(s) whose UP connections may be activated in MMNAS service request message, by the list of PDU sessions to beactivated.

In an example, if the service request over 3GPP access may be triggeredin response to a paging indicating non-3GPP access, the NAS servicerequest message may identify in the list of allowed PDU sessions thelist of PDU sessions associated with the non-3GPP access that may bere-activated over 3GPP. In an example, the PDU session status mayindicate the PDU sessions available in the UE 100. In an example, the UE100 may not trigger the service request procedure for a PDU sessioncorresponding to a LADN when the UE 100 may be outside the area ofavailability of the LADN. The UE 100 may not identify such PDUsession(s) in the list of PDU sessions to be activated, if the servicerequest may be triggered for other reasons.

In an example, the (R)AN 105 may send to AMF 155 an N2 Message 1010(e.g., a service request) comprising N2 parameters, MM NAS servicerequest, and/or the like. The AMF 155 may reject the N2 message if itmay not be able to handle the service request. In an example, if NG-RANmay be used, the N2 parameters may include the 5G-GUTI, selected PLMNID, location information, RAT type, establishment cause, and/or thelike. In an example, the 5G-GUTI may be obtained in RRC procedure andthe (R)AN 105 may select the AMF 155 according to the 5G-GUTI. In anexample, the location information and RAT type may relate to the cell inwhich the UE 100 may be camping. In an example, based on the PDU sessionstatus, the AMF 155 may initiate PDU session release procedure in thenetwork for the PDU sessions whose PDU session ID(s) may be indicated bythe UE 100 as not available.

In an example, if the service request was not sent integrity protectedor integrity protection verification failed, the AMF 155 may initiate aNAS authentication/security procedure 1015.

In an example, if the UE 100 triggers the service request to establish asignaling connection, upon successful establishment of the signalingconnection, the UE 100 and the network may exchange NAS signaling.

In an example the AMF 155 may send to the SMF 160 a PDU session updatecontext request 1020 e.g., Nsmf_PDUSession_UpdateSMContext requestcomprising PDU session ID(s), Cause(s), UE 100 location information,access type, and/or the like.

In an example, the Nsmf_PDUSession_UpdateSMContext request may beinvoked by the AMF 155 if the UE 100 may identify PDU session(s) to beactivated in the NAS service request message. In an example, theNsmf_PDUSession_UpdateSMContext request may be triggered by the SMF 160wherein the PDU session(s) identified by the UE 100 may correlate toother PDU session ID(s) than the one triggering the procedure. In anexample, the Nsmf_PDUSession_UpdateSMContext request may be triggered bythe SMF 160 wherein the current UE 100 location may be outside the areaof validity for the N2 information provided by the SMF 160 during anetwork triggered service request procedure. The AMF 155 may not sendthe N2 information provided by the SMF 160 during the network triggeredservice request procedure.

In an example, the AMF 155 may determine the PDU session(s) to beactivated and may send an Nsmf_PDUSession_UpdateSMContext request to SMF160(s) associated with the PDU session(s) with cause set to indicateestablishment of user plane resources for the PDU session(s).

In an example, if the procedure may be triggered in response to pagingindicating non-3GPP access, and the list of allowed PDU sessionsprovided by the UE 100 may not include the PDU session for which the UE100 was paged, the AMF 155 may notify the SMF 160 that the user planefor the PDU session may not be re-activated. The service requestprocedure may succeed without re-activating the user plane of any PDUsessions, and the AMF 155 may notify the UE 100.

In an example, if the PDU session ID may correspond to a LADN and theSMF 160 may determine that the UE 100 may be outside the area ofavailability of the LADN based on the UE 100 location reporting from theAMF 155, the SMF 160 may decide to (based on local policies) keep thePDU session, may reject the activation of user plane connection for thePDU session and may inform the AMF 155. In an example, if the proceduremay be triggered by a network triggered service request, the SMF 160 maynotify the UPF 110 that originated the data notification to discarddownlink data for the PDU sessions and/or to not provide further datanotification messages. The SMF 160 may respond to the AMF 155 with anappropriate reject cause and the user plane activation of PDU sessionmay be stopped.

In an example, if the PDU session ID may correspond to a LADN and theSMF 160 may determine that the UE 100 may be outside the area ofavailability of the LADN based on the UE 100 location reporting from theAMF 155, the SMF 160 may decide to (based on local policies) release thePDU session. The SMF 160 may locally release the PDU session and mayinform the AMF 155 that the PDU session may be released. The SMF 160 mayrespond to the AMF 155 with an appropriate reject cause and the userplane Activation of PDU session may be stopped.

In an example, if the UP activation of the PDU session may be acceptedby the SMF 160, based on the location info received from the AMF 155,the SMF 160 may check the UPF 110 Selection 1025 Criteria (e.g., sliceisolation requirements, slice coexistence requirements, UPF's 110dynamic load, UPF's 110 relative static capacity among UPFs supportingthe same DNN, UPF 110 location available at the SMF 160, UE 100 locationinformation, Capability of the UPF 110 and the functionality requiredfor the particular UE 100 session. In an example, an appropriate UPF 110may be selected by matching the functionality and features required fora UE 100, DNN, PDU session type (i.e. IPv4, IPv6, ethernet type orunstructured type) and if applicable, the static IP address/prefix, SSCmode selected for the PDU session, UE 100 subscription profile in UDM140, DNAI as included in the PCC rules, local operator policies,S-NSSAI, access technology being used by the UE 100, UPF 110 logicaltopology, and/or the like), and may determine to perform one or more ofthe following: continue using the current UPF(s); may select a newintermediate UPF 110 (or add/remove an intermediate UPF 110), if the UE100 has moved out of the service area of the UPF 110 that was previouslyconnecting to the (R)AN 105, while maintaining the UPF(s) acting as PDUsession anchor; may trigger re-establishment of the PDU session toperform relocation/reallocation of the UPF 110 acting as PDU sessionanchor, e.g. the UE 100 has moved out of the service area of the anchorUPF 110 which is connecting to RAN 105.

In an example, the SMF 160 may send to the UPF 110 (e.g., newintermediate UPF 110) an N4 session establishment request 1030. In anexample, if the SMF 160 may select a new UPF 110 to act as intermediateUPF 110-2 for the PDU session, or if the SMF 160 may select to insert anintermediate UPF 110 for a PDU session which may not have anintermediate UPF 110-2, an N4 session establishment request 1030 messagemay be sent to the new UPF 110, providing packet detection, dataforwarding, enforcement and reporting rules to be installed on the newintermediate UPF. The PDU session anchor addressing information (on N9)for this PDU session may be provided to the intermediate UPF 110-2.

In an example, if a new UPF 110 is selected by the SMF 160 to replacethe old (intermediate) UPF 110-2, the SMF 160 may include a dataforwarding indication. The data forwarding indication may indicate tothe UPF 110 that a second tunnel endpoint may be reserved for bufferedDL data from the old I-UPF.

In an example, the new UPF 110 (intermediate) may send to SMF 160 an N4session establishment response message 1030. In case the UPF 110 mayallocate CN tunnel info, the UPF 110 may provide DL CN tunnel info forthe UPF 110 acting as PDU session anchor and UL CN tunnel info (e.g., CNN3 tunnel info) to the SMF 160. If the data forwarding indication may bereceived, the new (intermediate) UPF 110 acting as N3 terminating pointmay send DL CN tunnel info for the old (intermediate) UPF 110-2 to theSMF 160. The SMF 160 may start a timer, to release the resource in theold intermediate UPF 110-2.

In an example, if the SMF 160 may selects a new intermediate UPF 110 forthe PDU session or may remove the old I-UPF 110-2, the SMF 160 may sendN4 session modification request message 1035 to PDU session anchor, PSAUPF 110-3, providing the data forwarding indication and DL tunnelinformation from new intermediate UPF 110.

In an example, if the new intermediate UPF 110 may be added for the PDUsession, the (PSA) UPF 110-3 may begin to send the DL data to the newI-UPF 110 as indicated in the DL tunnel information.

In an example, if the service request may be triggered by the network,and the SMF 160 may remove the old I-UPF 110-2 and may not replace theold I-UPF 110-2 with the new I-UPF 110, the SMF 160 may include the dataforwarding indication in the request. The data forwarding indication mayindicate to the (PSA) UPF 110-3 that a second tunnel endpoint may bereserved for buffered DL data from the old I-UPF 110-2. In this case,the PSA UPF 110-3 may begin to buffer the DL data it may receive at thesame time from the N6 interface.

In an example, the PSA UPF 110-3 (PSA) may send to the SMF 160 an N4session modification response 1035. In an example, if the dataforwarding indication may be received, the PSA UPF 110-3 may become asN3 terminating point and may send CN DL tunnel info for the old(intermediate) UPF 110-2 to the SMF 160. The SMF 160 may start a timer,to release the resource in old intermediate UPF 110-2 if there is one.

In an example, the SMF 160 may send to the old UPF 110-2 an N4 sessionmodification request 1045 (e.g., may comprise new UPF 110 address, newUPF 110 DL tunnel ID, and/or the like). In an example, if the servicerequest may be triggered by the network, and/or the SMF 160 may removethe old (intermediate) UPF 110-2, the SMF 160 may send the N4 sessionmodification request message to the old (intermediate) UPF 110-2, andmay provide the DL tunnel information for the buffered DL data. If theSMF 160 may allocate new I-UPF 110, the DL tunnel information is fromthe new (intermediate) UPF 110 may act as N3 terminating point. If theSMF 160 may not allocate a new I-UPF 110, the DL tunnel information maybe from the new UPF 110 (PSA) 110-3 acting as N3 terminating point. TheSMF 160 may start a timer to monitor the forwarding tunnel. In anexample, the old (intermediate) UPF 110-2 may send N4 sessionmodification response message to the SMF 160.

In an example, if the I-UPF 110-2 may be relocated and forwarding tunnelwas established to the new I-UPF 110, the old (intermediate) UPF 110-2may forward its buffered data to the new (intermediate) UPF 110 actingas N3 terminating point. In an example, if the old I-UPF 110-2 may beremoved and the new I-UPF 110 may not be assigned for the PDU sessionand forwarding tunnel may be established to the UPF 110 (PSA) 110-3, theold (intermediate) UPF 110-2 may forward its buffered data to the UPF110 (PSA) 110-3 acting as N3 terminating point.

In an example, the SMF 160 may send to the AMF 155 an N11 message 1060e.g., a Nsmf_PDUSession_UpdateSMContext response (comprising: N1 SMcontainer (PDU session ID, PDU session re-establishment indication), N2SM information (PDU session ID, QoS profile, CN N3 tunnel info,S-NSSAI), Cause), upon reception of the Nsmf_PDUSession_UpdateSMContextrequest with a cause including e.g., establishment of user planeresources. The SMF 160 may determine whether UPF 110 reallocation may beperformed, based on the UE 100 location information, UPF 110 servicearea and operator policies. In an example, for a PDU session that theSMF 160 may determine to be served by the current UPF 110, e.g., PDUsession anchor or intermediate UPF, the SMF 160 may generate N2 SMinformation and may send an Nsmf_PDUSession_UpdateSMContext response1060 to the AMF 155 to establish the user plane(s). The N2 SMinformation may contain information that the AMF 155 may provide to theRAN 105. In an example, for a PDU session that the SMF 160 may determineas requiring a UPF 110 relocation for PDU session anchor UPF, the SMF160 may reject the activation of UP of the PDU session by sendingNsmf_PDUSession_UpdateSMContext response that may contain N1 SMcontainer to the UE 100 via the AMF 155. The N1 SM container may includethe corresponding PDU session ID and PDU session re-establishmentindication.

Upon reception of the Namf_EventExposure_Notify from the AMF 155 to theSMF 160, with an indication that the UE 100 is reachable, if the SMF 160may have pending DL data, the SMF 160 may invoke theNamf_Communication_N1N2MessageTransfer service operation to the AMF 155to establish the user plane(s) for the PDU sessions. In an example, theSMF 160 may resume sending DL data notifications to the AMF 155 in caseof DL data.

In an example, the SMF 160 may send a message to the AMF 155 to rejectthe activation of UP of the PDU session by including a cause in theNsmf_PDUSession_UpdateSMContext response if the PDU session maycorrespond to a LADN and the UE 100 may be outside the area ofavailability of the LADN, or if the AMF 155 may notify the SMF 160 thatthe UE 100 may be reachable for regulatory prioritized service, and thePDU session to be activated may not for a regulatory prioritizedservice; or if the SMF 160 may decide to perform PSA UPF 110-3relocation for the requested PDU session.

In an example, the AMF 155 may send to the (R)AN 105 an N2 requestmessage 1065 (e.g., N2 SM information received from SMF 160, securitycontext, AMF 155 signaling connection ID, handover restriction list, MMNAS service accept, list of recommended cells/TAs/NG-RAN nodeidentifiers). In an example, the RAN 105 may store the security context,AMF 155 signaling connection Id, QoS information for the QoS flows ofthe PDU sessions that may be activated and N3 tunnel IDs in the UE 100RAN 105 context. In an example, the MM NAS service accept may includePDU session status in the AMF 155. If the activation of UP of a PDUsession may be rejected by the SMF 160, the MM NAS service accept mayinclude the PDU session ID and the reason why the user plane resourcesmay not be activated (e.g. LADN not available). Local PDU sessionrelease during the session request procedure may be indicated to the UE100 via the session Status.

In an example, if there are multiple PDU sessions that may involvemultiple SMF 160 s, the AMF 155 may not wait for responses from all SMF160 s before it may send N2 SM information to the UE 100. The AMF 155may wait for all responses from the SMF 160 s before it may send MM NASservice accept message to the UE 100.

In an example, the AMF 155 may include at least one N2 SM informationfrom the SMF 160 if the procedure may be triggered for PDU session userplane activation. AMF 155 may send additional N2 SM information from SMF160 s in separate N2 message(s) (e.g. N2 tunnel setup request), if thereis any. Alternatively, if multiple SMF 160 s may be involved, the AMF155 may send one N2 request message to (R)AN 105 after all theNsmf_PDUSession_UpdateSMContext response service operations from all theSMF 160 s associated with the UE 100 may be received. In such case, theN2 request message may include the N2 SM information received in one ormore of the Nsmf_PDUSession_UpdateSMContext response and PDU session IDto enable AMF 155 to associate responses to relevant SMF 160.

In an example, if the RAN 105 (e.g., NG RAN) node may provide the listof recommended cells/TAs/NG-RAN node identifiers during the AN releaseprocedure, the AMF 155 may include the information from the list in theN2 request. The RAN 105 may use this information to allocate the RAN 105notification area when the RAN 105 may decide to enable RRC inactivestate for the UE 100.

If the AMF 155 may receive an indication, from the SMF 160 during a PDUsession establishment procedure that the UE 100 may be using a PDUsession related to latency sensitive services, for any of the PDUsessions established for the UE 100 and the AMF 155 has received anindication from the UE 100 that may support the CM-CONNECTED with RRCinactive state, then the AMF 155 may include the UE's RRC inactiveassistance information. In an example, the AMF 155 based on networkconfiguration, may include the UE's RRC inactive assistance information.

In an example, the (R)AN 105 may send to the UE 100 a message to performRRC connection reconfiguration 1070 with the UE 100 depending on the QoSinformation for all the QoS flows of the PDU sessions whose UPconnections may be activated and data radio bearers. In an example, theuser plane security may be established.

In an example, if the N2 request may include a MM NAS service acceptmessage, the RAN 105 may forward the MM NAS service accept to the UE100. The UE 100 may locally delete context of PDU sessions that may notbe available in 5GC.

In an example, if the N1 SM information may be transmitted to the UE 100and may indicate that some PDU session(s) may be re-established, the UE100 may initiate PDU session re-establishment for the PDU session(s)that me be re-established after the service request procedure may becomplete.

In an example, after the user plane radio resources may be setup, theuplink data from the UE 100 may be forwarded to the RAN 105. The RAN 105(e.g., NG-RAN) may send the uplink data to the UPF 110 address andtunnel ID provided.

In an example, the (R)AN 105 may send to the AMF 155 an N2 request Ack1105 (e.g., N2 SM information (comprising: AN tunnel info, list ofaccepted QoS flows for the PDU sessions whose UP connections areactivated, list of rejected QoS flows for the PDU sessions whose UPconnections are activated)). In an example, the N2 request message mayinclude N2 SM information(s), e.g. AN tunnel info. RAN 105 may respondN2 SM information with separate N2 message (e.g. N2 tunnel setupresponse). In an example, if multiple N2 SM information are included inthe N2 request message, the N2 request Ack may include multiple N2 SMinformation and information to enable the AMF 155 to associate theresponses to relevant SMF 160.

In an example, the AMF 155 may send to the SMF 160 aNsmf_PDUSession_UpdateSMContext request 1110 (N2 SM information (ANtunnel info), RAT type) per PDU session. If the AMF 155 may receive N2SM information (one or multiple) from the RAN 105, then the AMF 155 mayforward the N2 SM information to the relevant SMF 160. If the UE 100time zone may change compared to the last reported UE 100 Time Zone thenthe AMF 155 may include the UE 100 time zone IE in theNsmf_PDUSession_UpdateSMContext request message.

In an example, if dynamic PCC is deployed, the SMF 160 may initiatenotification about new location information to the PCF 135 (ifsubscribed) by invoking an event exposure notification operation (e.g.,a Nsmf_EventExposure_Notify service operation). The PCF 135 may provideupdated policies by invoking a policy control update notificationmessage 1115 (e.g., a Npcf_SMPolicyControl_UpdateNotify operation).

In an example, if the SMF 160 may select a new UPF 110 to act asintermediate UPF 110 for the PDU session, the SMF 160 may initiates anN4 session modification procedure 1120 to the new I-UPF 110 and mayprovide AN tunnel info. The downlink data from the new I-UPF 110 may beforwarded to RAN 105 and UE 100. In an example, the UPF 110 may send tothe SMF 160, an N4 session modification response 1120. In an example,the SMF 160 may send to the AMF 155, an Nsmf_PDUSession_UpdateSMContextresponse 1140.

In an example, if forwarding tunnel may be established to the new I-UPF110 and if the timer SMF 160 set for forwarding tunnel may be expired,the SMF 160 may sends N4 session modification request 1145 to new(intermediate) UPF 110 acting as N3 terminating point to release theforwarding tunnel. In an example, the new (intermediate) UPF 110 maysend to the SMF 160 an N4 session modification response 1145. In anexample, the SMF 160 may send to the PSA UPF 110-3 an N4 sessionmodification request 1150, or N4 session release request. In an example,if the SMF 160 may continue using the old UPF 110-2, the SMF 160 maysend an N4 session modification request 1155, providing AN tunnel info.In an example, if the SMF 160 may select a new UPF 110 to act asintermediate UPF 110, and the old UPF 110-2 may not be PSA UPF 110-3,the SMF 160 may initiate resource release, after timer expires, bysending an N4 session release request (release cause) to the oldintermediate UPF 110-2.

In an example, the old intermediate UPF 110-2 may send to the SMF 160 anN4 session modification response or N4 session release response 1155.The old UPF 110-2 may acknowledge with the N4 session modificationresponse or N4 session release response message to confirm themodification or release of resources. The AMF 155 may invoke theNamf_EventExposure_Notify service operation to notify the mobilityrelated events, after this procedure may complete, towards the NFs thatmay have subscribed for the events. In an example, the AMF 155 mayinvoke the Namf_EventExposure_Notify towards the SMF 160 if the SMF 160had subscribed for UE 100 moving into or out of area of interest and ifthe UE's current location may indicate that it may be moving into ormoving outside of the area of interest subscribed, or if the SMF 160 hadsubscribed for LADN DNN and if the UE 100 may be moving into or outsideof an area where the LADN is available, or if the UE 100 may be in MICOmode and the AMF 155 had notified an SMF 160 of the UE 100 beingunreachable and that SMF 160 may not send DL data notifications to theAMF 155, and the AMF 155 may informs the SMF 160 that the UE 100 isreachable, or if the SMF 160 had subscribed for UE 100 reachabilitystatus, then the AMF 155 may notify the UE 100 reachability.

An example PDU session establishment procedure depicted in FIG. 12 andFIG. 13. In an example embodiment, when the PDU session establishmentprocedure may be employed, the UE 100 may send to the AMF 155 a NASMessage 1205 (or a SM NAS message) comprising NSSAI, S-NSSAI (e.g.,requested S-NSSAI, allowed S-NSSAI, subscribed S-NSSAI, and/or thelike), DNN, PDU session ID, request type, old PDU session ID, N1 SMcontainer (PDU session establishment request), and/or the like. In anexample, the UE 100, in order to establish a new PDU session, maygenerate a new PDU session ID. In an example, when emergency service maybe required and an emergency PDU session may not already be established,the UE 100 may initiate the UE 100 requested PDU session establishmentprocedure with a request type indicating emergency request. In anexample, the UE 100 may initiate the UE 100 requested PDU sessionestablishment procedure by the transmission of the NAS messagecontaining a PDU session establishment request within the N1 SMcontainer. The PDU session establishment request may include a PDU type,SSC mode, protocol configuration options, and/or the like. In anexample, the request type may indicate initial request if the PDUsession establishment is a request to establish the new PDU session andmay indicate existing PDU session if the request refers to an existingPDU session between 3GPP access and non-3GPP access or to an existingPDN connection in EPC. In an example, the request type may indicateemergency request if the PDU session establishment may be a request toestablish a PDU session for emergency services. The request type mayindicate existing emergency PDU session if the request refers to anexisting PDU session for emergency services between 3GPP access andnon-3GPP access. In an example, the NAS message sent by the UE 100 maybe encapsulated by the AN in a N2 message towards the AMF 155 that mayinclude user location information and access technology typeinformation. In an example, the PDU session establishment requestmessage may contain SM PDU DN request container containing informationfor the PDU session authorization by the external DN. In an example, ifthe procedure may be triggered for SSC mode 3 operation, the UE 100 mayinclude the old PDU session ID which may indicate the PDU session ID ofthe ongoing PDU session to be released, in the NAS message. The old PDUsession ID may be an optional parameter which may be included in thiscase. In an example, the AMF 155 may receive from the AN the NAS message(e.g., NAS SM message) together with user location information (e.g.cell ID in case of the RAN 105). In an example, the UE 100 may nottrigger a PDU session establishment for a PDU session corresponding to aLADN when the UE 100 is outside the area of availability of the LADN.

In an example, the AMF 155 may determine that the NAS message or the SMNAS message may correspond to the request for the new PDU session basedon that request type indicates initial request and that the PDU sessionID may not be used for any existing PDU session(s) of the UE 100. If theNAS message does not contain an S-NSSAI, the AMF 155 may determine adefault S-NSSAI for the requested PDU session either according to the UE100 subscription, if it may contain only one default S-NSSAI, or basedon operator policy. In an example, the AMF 155 may perform SMF 160selection 1210 and select an SMF 160. If the request type may indicateinitial request or the request may be due to handover from EPS, the AMF155 may store an association of the S-NSSAI, the PDU session ID and aSMF 160 ID. In an example, if the request type is initial request and ifthe old PDU session ID indicating the existing PDU session may becontained in the message, the AMF 155 may select the SMF 160 and maystore an association of the new PDU session ID and the selected SMF 160ID.

In an example, the AMF 155 may send to the SMF 160, an N11 message 1215,e.g., Nsmf_PDUSession_CreateSMContext request (comprising: SUPI or PEI,DNN, S-NSSAI, PDU session ID, AMF 155 ID, request type, N1 SM container(PDU session establishment request), user location information, accesstype, PEI, GPSI), or Nsmf_PDUSession_UpdateSMContext request (SUPI, DNN,S-NSSAI, PDU session ID, AMF 155 ID, request type, N1 SM container (PDUsession establishment request), user location information, access type,RAT type, PEI). In an example, if the AMF 155 may not have anassociation with the SMF 160 for the PDU session ID provided by the UE100 (e.g when request type indicates initial request), the AMF 155 mayinvoke the Nsmf_PDUSession_CreateSMContext request, but if the AMF 155already has an association with an SMF 160 for the PDU session IDprovided by the UE 100 (e.g when request type indicates existing PDUsession), the AMF 155 may invoke the Nsmf_PDUSession_UpdateSMContextrequest. In an example, the AMF 155 ID may be the UE's GUAMI whichuniquely identifies the AMF 155 serving the UE 100. The AMF 155 mayforward the PDU session ID together with the N1 SM container containingthe PDU session establishment request received from the UE 100. The AMF155 may provide the PEI instead of the SUPI when the UE 100 hasregistered for emergency services without providing the SUPI. In casethe UE 100 has registered for emergency services but has not beenauthenticated, the AMF 155 may indicate that the SUPI has not beenauthenticated.

In an example, if the request type may indicate neither emergencyrequest nor existing emergency PDU session and, if the SMF 160 has notyet registered and subscription data may not be available, the SMF 160may register with the UDM 140, and may retrieve subscription data 1225and subscribes to be notified when subscription data may be modified. Inan example, if the request type may indicate existing PDU session orexisting emergency PDU session, the SMF 160 may determine that therequest may be due to handover between 3GPP access and non-3GPP accessor due to handover from EPS. The SMF 160 may identify the existing PDUsession based on the PDU session ID. The SMF 160 may not create a new SMcontext but instead may update the existing SM context and may providethe representation of the updated SM context to the AMF 155 in theresponse. if the request type may be initial request and if the old PDUsession ID may be included in Nsmf_PDUSession_CreateSMContext request,the SMF 160 may identify the existing PDU session to be released basedon the old PDU session ID.

In an example, the SMF 160 may send to the AMF 155, the N11 messageresponse 1220, e.g., either a PDU session create/update response,Nsmf_PDUSession_CreateSMContext response 1220 (cause, SM context ID orN1 SM container (PDU session reject(cause))) or anNsmf_PDUSession_UpdateSMContext response.

In an example, if the SMF 160 may perform secondaryauthorization/authentication 1230 during the establishment of the PDUsession by a DN-AAA server, the SMF 160 may select a UPF 110 and maytrigger a PDU session establishment authentication/authorization.

In an example, if the request type may indicate initial request, the SMF160 may select an SSC mode for the PDU session. The SMF 160 may selectone or more UPFs as needed. In case of PDU type IPv4 or IPv6, the SMF160 may allocate an IP address/prefix for the PDU session. In case ofPDU type IPv6, the SMF 160 may allocate an interface identifier to theUE 100 for the UE 100 to build its link-local address. For UnstructuredPDU type the SMF 160 may allocate an IPv6 prefix for the PDU session andN6 point-to-point tunneling (based on UDP/IPv6).

In an example, if dynamic PCC is deployed, the may SMF 160 performs PCF135 selection 1235. If the request type indicates existing PDU sessionor existing emergency PDU session, the SMF 160 may use the PCF 135already selected for the PDU session. If dynamic PCC is not deployed,the SMF 160 may apply local policy.

In an example, the SMF 160 may perform a session management policyestablishment procedure 1240 to establish a PDU session with the PCF 135and may get the default PCC Rules for the PDU session. The GPSI may beincluded if available at the SMF 160. If the request type in 1215indicates existing PDU session, the SMF 160 may notify an eventpreviously subscribed by the PCF 135 by a session management policymodification procedure and the PCF 135 may update policy information inthe SMF 160. The PCF 135 may provide authorized session-AMBR and theauthorized 5QI and ARP to SMF 160. The PCF 135 may subscribe to the IPallocation/release event in the SMF 160 (and may subscribe otherevents).

In an example, the PCF 135, based on the emergency DNN, may set the ARPof the PCC rules to a value that may be reserved for emergency services.

In an example, if the request type in 1215 indicates initial request,the SMF 160 may select an SSC mode for the PDU session. The SMF 160 mayselect 1245 one or more UPFs as needed. In case of PDU type IPv4 orIPv6, the SMF 160 may allocate an IP address/prefix for the PDU session.In case of PDU type IPv6, the SMF 160 may allocate an interfaceidentifier to the UE 100 for the UE 100 to build its link-local address.For unstructured PDU type the SMF 160 may allocate an IPv6 prefix forthe PDU session and N6 point-to-point tunneling (e.g., based onUDP/IPv6). In an example, for Ethernet PDU type PDU session, neither aMAC nor an IP address may be allocated by the SMF 160 to the UE 100 forthis PDU session.

In an example, if the request type in 1215 is existing PDU session, theSMF 160 may maintain the same IP address/prefix that may be allocated tothe UE 100 in the source network.

In an example, if the request type in 1215 indicates existing PDUsession referring to an existing PDU session moved between 3GPP accessand non-3GPP access, the SMF 160 may maintain the SSC mode of the PDUsession, e.g., the current PDU session Anchor and IP address. In anexample, the SMF 160 may trigger e.g. new intermediate UPF 110 insertionor allocation of a new UPF 110. In an example, if the request typeindicates emergency request, the SMF 160 may select 1245 the UPF 110 andmay select SSC mode 1.

In an example, the SMF 160 may perform a session management policymodification 1250 procedure to report some event to the PCF 135 that haspreviously subscribed. If request type is initial request and dynamicPCC is deployed and PDU type is IPv4 or IPv6, the SMF 160 may notify thePCF 135 (that has previously subscribed) with the allocated UE 100 IPaddress/prefix.

In an example, the PCF 135 may provide updated policies to the SMF 160.The PCF 135 may provide authorized session-AMBR and the authorized 5QIand ARP to the SMF 160.

In an example, if request type indicates initial request, the SMF 160may initiate an N4 session establishment procedure 1255 with theselected UPF 110. The SMF 160 may initiate an N4 session modificationprocedure with the selected UPF 110. In an example, the SMF 160 may sendan N4 session establishment/modification request 1255 to the UPF 110 andmay provide packet detection, enforcement, reporting rules, and/or thelike to be installed on the UPF 110 for this PDU session. If CN tunnelinfo is allocated by the SMF 160, the CN tunnel info may be provided tothe UPF 110. If the selective user plane deactivation is required forthis PDU session, the SMF 160 may determine the Inactivity Timer and mayprovide it to the UPF 110. In an example, the UPF 110 may acknowledgesby sending an N4 session establishment/modification response 1255. If CNtunnel info is allocated by the UPF, the CN tunnel info may be providedto SMF 160. In an example, if multiple UPFs are selected for the PDUsession, the SMF 160 may initiate N4 session establishment/modificationprocedure 1255 with one or more UPF 110 of the PDU session.

In an example, the SMF 160 may send to the AMF 155 anNamf_Communication_N1N2MessageTransfer 1305 message (comprising PDUsession ID, access type, N2 SM information (PDU session ID, QFI(s), QoSprofile(s), CN tunnel info, S-NSSAI, session-AMBR, PDU session type,and/or the like), N1 SM container (PDU session establishment accept (QoSRule(s), selected SSC mode, S-NSSAI, allocated IPv4 address, interfaceidentifier, session-AMBR, selected PDU session type, and/or the like))).In case of multiple UPFs are used for the PDU session, the CN tunnelinfo may comprise tunnel information related with the UPF 110 thatterminates N3. In an example, the N2 SM information may carryinformation that the AMF 155 may forward to the (R)AN 105 (e.g., the CNtunnel info corresponding to the core network address of the N3 tunnelcorresponding to the PDU session, one or multiple QoS profiles and thecorresponding QFIs may be provided to the (R)AN 105, the PDU session IDmay be used by AN signaling with the UE 100 to indicate to the UE 100the association between AN resources and a PDU session for the UE 100,and/or the like). In an example, a PDU session may be associated to anS-NSSAI and a DNN. In an example, the N1 SM container may contain thePDU session establishment accept that the AMF 155 may provide to the UE100. In an example, multiple QoS rules and QoS profiles may be includedin the PDU session establishment accept within the N1 SM and in the N2SM information. In an example, theNamf_Communication_N1N2MessageTransfer 1305 may further comprise the PDUsession ID and information allowing the AMF 155 to know which accesstowards the UE 100 to use.

In an example, the AMF 155 may send to the (R)AN 105 an N2 PDU sessionrequest 1310 (comprising N2 SM information, NAS message (PDU session ID,N1 SM container (PDU session establishment accept, and/or the like))).In an example, the AMF 155 may send the NAS message 1310 that maycomprise PDU session ID and PDU session establishment accept targeted tothe UE 100 and the N2 SM information received from the SMF 160 withinthe N2 PDU session request 1310 to the (R)AN 105.

In an example, the (R)AN 105 may issue AN specific signaling exchange1315 with the UE 100 that may be related with the information receivedfrom SMF 160. In an example, in case of a 3GPP RAN 105, an RRCconnection reconfiguration procedure may take place with the UE 100 toestablish the necessary RAN 105 resources related to the QoS Rules forthe PDU session request 1310. In an example, (R)AN 105 may allocate(R)AN 105 N3 tunnel information for the PDU session. In case of dualconnectivity, the master RAN 105 node may assign some (zero or more)QFIs to be setup to a master RAN 105 node and others to the secondaryRAN 105 node. The AN tunnel info may comprise a tunnel endpoint for oneor more involved RAN 105 nodes, and the QFIs assigned to one or moretunnel endpoints. A QFI may be assigned to either the master RAN 105node or the secondary RAN 105 node. In an example, (R)AN 105 may forwardthe NAS message 1310 (PDU session ID, N1 SM container (PDU sessionestablishment accept)) to the UE 100. The (R)AN 105 may provide the NASmessage to the UE 100 if the necessary RAN 105 resources are establishedand the allocation of (R)AN 105 tunnel information are successful.

In an example, the N2 PDU session response 1320 may comprise a PDUsession ID, cause, N2 SM information (PDU session ID, AN tunnel info,list of accepted/rejected QFI(s)), and/or the like. In an example, theAN tunnel info may correspond to the access network address of the N3tunnel corresponding to the PDU session.

In an example, the AMF 155 may forward the N2 SM information receivedfrom (R)AN 105 to the SMF 160 via a Nsmf_PDUSession_UpdateSMContextrequest 1330 (comprising: N2 SM information, request type, and/or thelike). In an example, if the list of rejected QFI(s) is included in N2SM information, the SMF 160 may release the rejected QFI(s) associatedQoS profiles.

In an example, the SMF 160 may initiate an N4 session modificationprocedure 1335 with the UPF 110. The SMF 160 may provide AN tunnel infoto the UPF 110 as well as the corresponding forwarding rules. In anexample, the UPF 110 may provide an N4 session modification response1335 to the SMF 160160.

In an example, the SMF 160 may send to the AMF 155 anNsmf_PDUSession_UpdateSMContext response 1340 (Cause). In an example,the SMF 160 may subscribe to the UE 100 mobility event notification fromthe AMF 155 (e.g. location reporting, UE 100 moving into or out of areaof interest), after this step by invoking Namf_EventExposure_Subscribeservice operation. For LADN, the SMF 160 may subscribe to the UE 100moving into or out of LADN service area event notification by providingthe LADN DNN as an indicator for the area of interest. The AMF 155 mayforward relevant events subscribed by the SMF 160.

In an example, the SMF 160 may send to the AMF 155, aNsmf_PDUSession_SMContextStatusNotify (release) 1345. In an example, ifduring the procedure, any time the PDU session establishment is notsuccessful, the SMF 160 may inform the AMF 155 by invokingNsmf_PDUSession_SMContextStatusNotify(release) 1345. The SMF 160 mayreleases any N4 session(s) created, any PDU session address if allocated(e.g IP address) and may release the association with the PCF 135.

In an example, in case of PDU type IPv6, the SMF 160 may generate anIPv6 Router Advertisement 1350 and may send it to the UE 100 via N4 andthe UPF 110.

In an example, if the PDU session may not be established, the SMF 160may unsubscribe 1360 to the modifications of session managementsubscription data for the corresponding (SUPI, DNN, S-NSSAI), usingNudm_SDM_Unsubscribe (SUPI, DNN, S-NSSAI), if the SMF 160 is no morehandling a PDU session of the UE 100 for this (DNN, S-NSSAI). In anexample, if the PDU session may not be established, the SMF 160 mayderegister 1360 for the given PDU session using Nudm_UECM_Deregistration(SUPI, DNN, PDU session ID).

In an example, 3GPP systems may support public networks (for example,PLMN) and non public networks (NPN). To enable NPNs deployed as part ofa PLMN, a closed access group (CAG) may be employed to restrict accessto NPN resources, cells, slices, DNN, and/or the like. In an example, aUE may be restricted to access only CAGs and not allowed to access PLMNresources. During a handover procedure of a CAG-only UE, the UE mayattempt to hand over to a target cell of a target RAN node of a PLMNthat the UE is not authorized to access, which may result in excessivesignaling and communication failure such as a handover reject/failure.

Example embodiments are directed to improved techniques for implementingRAN (NG-RAN) connection setup and configuration signaling. Additionalexample embodiments are directed to improved techniques for implementinghandover signaling procedures when attempting handover to a target basestation. These techniques may assist in determining a target basestation that supports one or more CAGs associated with the UE, therebyfacilitating fast and efficient handover. Additionally or alternatively,these techniques may prevent a UE from attempting to access a cell thatthe UE is restricted from accessing, thereby reducing signaling overheadassociated with futile handover attempts. For example, a CAG-only UE maybe restricted to CAG cells and may be unable to access non-CAG cells(also referred to herein as normal cells) of a target RAN node. Thetechniques of the present disclosure may facilitate selection of atarget RAN node that supports the CAGs associated with the UE andavoidance of overhead signaling associated with attempts by a CAG-onlyUE to access non-CAG cells of a target RAN node.

In an example, mobility restrictions may restrict mobility handling orservice access of a UE. The mobility restriction functionality may beprovided by the UE, the radio access network, and/or the core network.Mobility restrictions may apply to 3GPP access. Service arearestrictions and handling of forbidden areas for CM-IDLE state and, forCM-CONNECTED state when in RRC Inactive state may be executed by the UEbased on information received from the core network. Mobilityrestrictions for CM-CONNECTED state when in RRC-Connected state may beexecuted by the radio access network and/or the core network. InCM-CONNECTED state, the core network may provide mobility restrictionsto the radio access network within mobility restriction list. Mobilityrestrictions may comprise RAT restriction, forbidden area, service arearestrictions, core network type restriction and closed access groupinformation, and/or the like. In an example, RAT restriction maydefine/determine the 3GPP radio access technology(ies) that a UE may notbe allowed to access in a PLMN. In a restricted RAT the UE based onsubscription may not be permitted to access to the network for thisPLMN. For CM-CONNECTED state, when radio access network determines atarget RAT and a target PLMN during a handover procedure, it may takeper-PLMN RAT restriction into consideration. The RAT restriction may beenforced in the network, and not provided to the UE. In an example, in aforbidden area, the UE, based on subscription, may not be permitted toinitiate any communication with the network for this PLMN. The UEbehaviour in terms of cell selection, RAT selection, PLMN selection,and/or the like, may depend on (be determined by) the network responsethat informs the UE of forbidden area. In an example, service arearestriction may define/determine areas in which the UE may or may notinitiate communication with the network based on Allowed Area (in anAllowed Area, the UE is permitted to initiate communication with thenetwork as allowed by the subscription), Non-Allowed Area, Core Networktype restriction, closed access group information, and/or the like. In aNon-Allowed Area, a UE may be service area restricted based onsubscription. The UE and the network may not be allowed to initiateservice request or SM signalling to obtain user services (both inCM-IDLE and in CM-CONNECTED states). The UE may not use the entering ofa Non-Allowed Area as a criterion for Cell Reselection, a trigger forPLMN Selection or Domain selection for UE originating sessions or calls.The RRC procedures while the UE is in CM-CONNECTED with RRC Inactivestate may be unchanged compared to when the UE is in an Allowed Area.The RM procedures may remain unchanged compared to when the UE is in anAllowed Area. The UE in a Non-Allowed Area may respond to core networkpaging or NAS Notification message from non-3GPP access with servicerequest and RAN paging. Core network type restrictions may definewhether the UE is allowed to connect to 5GC for this PLMN.

For a given UE, the core network may determine the mobility restrictionsbased on UE subscription information, UE location and local policy. Themobility restriction may change due to e.g. UE's subscription, locationchange and local policy. The service area restrictions or thenon-allowed area may be fine-tuned by the PCF e.g. based on UE location,PEI and network policies. Service area restrictions may be updatedduring a registration procedure or UE configuration update procedure.

In an example, if the network sends service area restrictions to the UE,the network may send an allowed area, or a non-allowed area to the UE.If the UE has received an allowed area from the network, any TA not partof the allowed area may be considered by the UE as non-allowed. If theUE has received an indication of a non-allowed area from the network,any TA not part of the non-allowed area may be considered by the UE asallowed. If the UE has not received any service area restrictions, anyTA in the PLMN may be considered as allowed. If the UE has overlappingareas between forbidden areas, service area restrictions, or anycombination of them, the evaluation of forbidden areas may takeprecedence over the evaluation of service area restrictions. The UE andthe network may override any forbidden area, non-allowed arearestrictions and core network type restriction whenever access to thenetwork for regulatory prioritized services like Emergency services,MPS, and/or the like.

In an example, public network may be integrated with non-public network(NPNs). NPNs may be made available via PLMNs e.g. by means of dedicatedDNNs, or by one (or more) network slice instances allocated for the NPN.The existing network slicing functionalities may apply. When an NPN ismade available via a PLMN, then the UE may have a subscription for thePLMN. As network slicing may not enable the possibility to prevent UEsfrom trying to access the network in areas which the UE is not allowedto use the network slice allocated for the NPN, closed access groups maybe employed in addition to network slicing to apply access control. Aclosed access group (CAG) may identify a group of subscribers who arepermitted to access one or more cells associated to the CAG. The CAG maybe employed for the public network integrated NPNs to prevent UE(s),which are not allowed to access the NPN via the associated cell(s), fromautomatically selecting and accessing the associated cell(s). In anexample, a CAG may be identified by a CAG identifier (CAG ID) which isunique within the scope of a PLMN ID. A CAG cell may broadcast one ormultiple CAG identifiers per PLMN. An NG-RAN node may supportbroadcasting one or more (e.g., a total of twelve) CAGIDs. A CAG cellmay broadcast a human-readable network name per CAG ID. Thehuman-readable network name per CAG ID may be employed for presentationto user when user requests a manual CAG selection.

In an example, to support CAG, the UE may be configured using a UEconfiguration update procedure (as depicted in FIG. 16) for access andmobility management related parameters. The UE configuration updateprocedure may be employed to provide an Allowed CAG list, an indicationwhether the UE is only allowed to access the 5GS via CAG cells, or anyother suitable information. The CAG information may be included in thesubscription as part of the mobility restrictions. The Allowed CAG listmay be, for example, a list of CAG IDs that the UE is allowed to access.The indication whether the UE is only allowed to access the 5GS via CAGcells may be a closed access group restriction indicator (for example, aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like).

In an example, the CAG list, CAG IDs, CAG restriction indicator, and/orthe like may be employed by the network to select a target RAN node, atarget cell of the target RAN node, a target AMF, and/or the like duringa handover procedure. For example, when a RAN node receives a secondclosed access group identifier associated with a wireless device, andthe second closed access group identifier is different from a firstclosed access group identifier, the handover may not be accepted. In anexample, when a RAN node receives a closed access group restrictionindicator indicating that the wireless device is restricted to cellsassociated with closed access groups, and the target cells of the targetRAN node do not support the CAGs, the handover may not be accepted atthe target RAN node. In an example, when the RAN node receives theclosed access group restriction indicator indicating that the wirelessdevice is restricted to cells associated with closed access groups, theRAN node may determine that the non-CAG cells, or normal cells of thetarget RAN node may not be selected for the handover of the wirelessdevice/UE.

In an example embodiment, the CAG cell may broadcast information suchthat the UEs supporting CAG are accessing the cell. Cells may be CAGcells, normal PLMN cells, and/or the like.

The mobility restrictions may be able to restrict the UE's mobilityaccording to the allowed CAG list (if configured in the subscription)and may include an indication whether the UE is only allowed to accessCAG cells (if configured in the subscription). During transition fromCM-IDLE to CM-CONNECTED, if the UE is accessing the 5GS via a CAG cell,the NG-RAN may provide the CAG Identifier to the AMF. The AMF may verifywhether UE access is allowed by Mobility Restrictions. If the CAGIdentifier received from the NG-RAN is part of the UE's Allowed CAGlist, then the AMF accepts the NAS request. If the CAG Identifierreceived from the NG-RAN is not part of the UE's Allowed CAG list, thenthe AMF rejects the NAS request with an appropriate cause code, whereasthe UE may remove that CAG Identifier, if it exists, from its AllowedCAG list. The AMF may release the NAS signalling connection for the UEby triggering the AN release procedure. If the UE is accessing thenetwork via a non-CAG cell and the UE's subscription contains anindication that the UE is only allowed to access CAG cells, then the AMFrejects the NAS request with an appropriate cause code, whereas the UEupdates its local configuration. The AMF may release the NAS signallingconnection for the UE by triggering the AN release procedure. Duringconnected mode mobility procedures based on the Mobility Restrictionsreceived from the AMF, source NG-RAN may not handover the UE to a targetNG-RAN node if the target is a CAG cell and the related CAG Identifieris not part of the UE's Allowed CAG list. Source NG-RAN may not handoverthe UE to a non-CAG cell if the UE is only allowed to access CAG cells.When the AMF receives the Nudm_SDM_Notification from the UDM and the AMFdetermines that the Allowed CAG list or the indication whether the UE isonly allowed to access CAG cells have changed, The AMF may update themobility restrictions in the UE and NG-RAN accordingly. If the UE iscurrently accessing a CAG cell and the related CAG Identifier has beenremoved from the Allowed CAG list or if the UE is currently accessing anon-CAG cell and the indication that the UE is only allowed to accessCAG cells has been set in the subscription, then the AMF may release theNAS signalling connection for the UE by triggering the AN releaseprocedure.

The PLMN operator may provide access to an NPN by employing networkslicing mechanisms. The UE may have subscription and credentials for thePLMN. The PLMN and NPN service provider may have an agreement of wherethe NPN network slice is to be deployed (i.e. in which TAs of the PLMNand optionally including support for roaming PLMNs). The PLMNsubscription may comprise support for Subscribed S-NSSAI to be used forthe NPN. The PLMN operator may offer possibilities for the NPN serviceprovider to manage the NPN network slice. When the UE registers thefirst time to the PLMN, the PLMN may configure the UE with URSPincluding NSSP associating applications to the NPN S-NSSAI. The PLMN mayconfigure the UE with Configured NSSAI for the Serving PLMN. The PLMNand NPN may perform a network slice specific authentication andauthorization using additional NPN credentials.

In an example embodiment, the UE may be configured with the following tosupport CAG. An Allowed CAG list e.g., a list of CAG Identifiers the UEis allowed to access, an indication whether the UE is only allowed toaccess 5GS via CAG cells, allowed NSSAI (e.g., mapping of CAG and NSSAI,S-NSSAIs) for one or more CAGs, and/or the like. The AMF may provide theUE's Allowed CAG list (if configured in the subscription) and anindication whether the UE is only allowed to access CAG cells (ifconfigured in the subscription) as part of the Mobility Restrictions toNG-RAN. Based on the Mobility Restrictions received from the AMF, sourceNG-RAN may not handover the UE to a target NG-RAN node if the target isa CAG cell and the related CAG Identifier is not part of the UE'sAllowed CAG list. Based on the Mobility Restrictions received from theAMF, source NG-RAN may not handover the UE to a non-CAG cell if the UEis only allowed to access CAG cells.

In an example embodiment as depicted in FIG. 14, the registrationprocedure (as in FIG. 8 and FIG. 9) may be performed.

As shown in FIG. 8, the UE 100 may transmit an AN message 805 to the RAN105. In an example embodiment, the wireless device (the UE) may send anAN message to the RAN node (e.g., base station, NG-RAN, gNB, NG-eNB,and/or the like). The AN message may comprise AN parameters,registration request (e.g., Registration type, SUCI or 5G-GUTI or PEI,last visited TAI (if available), Security parameters, Requested NSSAI,[Mapping Of Requested NSSAI], Default Configured NSSAI Indication, UERadio Capability Update, UE MM Core Network Capability, PDU Sessionstatus, List Of PDU Sessions To Be Activated, Follow-on request, MICOmode preference, Requested DRX parameters, [LADN DNN(s) or Indicator OfRequesting LADN Information]), UE Policy Container (e.g., the list ofPSIs, indication of UE support for ANDSP and the operating systemidentifier), and/or the like. In the case of NG-RAN, the AN parametersmay comprise e.g. 5G-S-TMSI or GUAMI, the Selected PLMN ID, NPN ID, NID,Requested NSSAI, and/or the like. In an example, the AN parameter mayfurther comprise an establishment cause. The establishment cause mayprovide/indicate the reason for requesting the establishment of an RRCconnection. In an example, the UE may employ a CAG cell to access theNG-RAN. The AN parameters may comprise an identifier of a closed accessgroup (e.g., a CAG Identifier, a non-public network identifier, anetwork identifier, and/or the like), a closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like), and/or the like. Theclosed access group restriction indicator may indicate whether thewireless device is restricted to cells associated with closed accessgroups. In an example, the closed access group restriction indicator mayindicate that the UE may access one or more cells associated with one ormore CAG(s)/CAG IDs. In an example, the closed access group restrictionindicator may indicate that the UE may be allowed access to non-CAGcells, PLMN cells, and/or the like. In an example, the closed accessgroup restriction indicator may indicate that the UE may be allowedaccess to CAG cells, non-CAG cells, PLMN cells, and/or the like. In anexample, the UE may send to the RAN/NG-RAN requested NSSAI for the CAG,[mapping of (requested) NSSAI for the CAG], default configured NSSAIindication for one or more CAGs associated with the wireless device/UE.

In an example, if a 5G-S-TMSI or GUAMI is not included or the 5G-S-TMSIor GUAMI does not indicate a valid AMF the (R)AN, based on (R)AT andRequested NSSAI, if available, may select an AMF. The (R)AN may forwardthe Registration Request message to the AMF based on the N2 connectionof the UE. If the (R)AN cannot select an appropriate AMF, it may forwardthe Registration Request to an AMF which has been configured, in (R)AN,to perform AMF selection. In an example, the RAN node may select the AMFon the CAG ID(s), one or more CAGs that the UE is allowed/configured toemploy, mobility restriction, a CAG restriction indicator, and/or thelike.

In an example, the RAN node may send to the AMF an N2 message. In anexample, the N2 message may comprise N2 parameters, the registrationrequest, UE Policy Container, and/or the like. In an example, whenNG-RAN is used, the N2 parameters may comprise the selected PLMN ID, NPNID, NID, location information and cell identity related to the cell inwhich the UE is camping, UE context request which indicates that a UEcontext including security information needs to be setup at the NG-RAN,and/or the like. In an example, when NG-RAN is employed, the N2parameters may further comprise the establishment cause. In an example,the N2 parameters may comprise a CAG identifier if the UE is accessingthe NG-RAN using a CAG cell, the closed access group restrictionindicator, and/or the like.

In an example, the RAN node may send to the AMF, mapping of requestedNSSAI. In an example, the RAN node may send to the AMF, mapping ofrequested NSSAI for one or more CAG(s), CAG IDs, and/or the like.

In an example as depicted in FIG. 10, FIG. 11 and FIG. 15, the servicerequest procedure may be performed.

In an example embodiment, the UE may send to the NG-RAN/RAN node, an ANmessage. The AN message may comprise AN parameters, Service Request(e.g., list Of PDU Sessions To Be Activated, List Of Allowed PDUSessions, security parameters, PDU Session status, 5G-S-TMSI, and/or thelike), and/or the like. If the UE needs/determines to send IEs which arenot part of the cleartext IEs, then the UE may send the service requestpartially ciphered, providing only the IEs. The List Of PDU sessions tobe activated may be provided by UE when the UE wants to re-activate thePDU Session(s). The List Of Allowed PDU Sessions may be provided by theUE when the service request is a response of a Paging or a NASnotification for a PDU session associated with non-3GPP access, andidentifies the PDU sessions that can be transferred to 3GPP access. Inan example, the AN parameters comprise 5G-S-TMSI, selected PLMN ID, NPNID, NID, establishment cause, and/or the like. The establishment causemay determine/provide the reason for requesting the establishment of anRRC connection. The AN parameters may comprise a CAG Identifier if theUE is accessing the NG-RAN using a CAG cell, the closed access grouprestriction indicator, and/or the like. In an example, the UE may sendthe service request message towards the AMF encapsulated in an RRCmessage to the NG-RAN. The RRC message(s) may be employed to carry the5G-S-TMSI and the NAS message.

In an example embodiment, the one or more closed access groupidentifiers associated with the UE, the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like), the requested NSSAIfor the CAG, [mapping of (requested) NSSAI for the CAG], defaultconfigured NSSAI indication for one or more CAGs associated with thewireless device/UE, and/or the like, may be transmitted from the UE tothe network via a NAS message, RRC message, and/or the like.

In an example embodiment as depicted in FIG. 18, the AMF may receive theone or more closed access group identifiers associated with the UE, theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], default configured NSSAI indication for one or moreCAGs associated with the wireless device/UE, and/or the like. In anexample, the AMF may send to a RAN node, the NG-RAN node, and/or thelike, an initial context setup message. The AMF may perform an initialcontext setup procedure. The initial context setup procedure may beemployed to establish the necessary overall initial UE context at theNG-RAN node, when required, including PDU session context, the SecurityKey, Mobility Restriction List, UE Radio Capability and UE SecurityCapabilities, etc. The AMF may initiate the Initial Context Setupprocedure if a UE-associated logical NG-connection exists for the UE orif the AMF has received the RAN UE NGAP ID IE in an INITIAL UE MESSAGEmessage or if the NG-RAN node has already initiated a UE-associatedlogical NG-connection by sending an INITIAL UE MESSAGE message viaanother NG interface instance. The procedure may employ UE-associatedsignalling.

In an example, the initial context setup message may comprise MessageType, AMF UE NGAP ID, RAN UE NGAP ID, Old AMF, UE Aggregate Maximum BitRate, Core Network Assistance Information, GUAMI, PDU Session ResourceSetup Request List, PDU Session Resource Setup Request Item, PDU SessionID, NAS-PDU, S-NSSAI, PDU Session Resource Setup Request Transfer,Allowed NSSAI, UE Security Capabilities, Security Key, Trace Activation,Mobility Restriction List, UE Radio Capability, Index to RAT/FrequencySelection Priority, Masked IMEISV, NAS-PDU, Emergency FallbackIndicator, RRC Inactive Transition Report Request, UE Radio Capabilityfor Paging, and/or the like.

In an example, the initial context setup message may further compriseone or more IEs comprising the one or more closed access groupidentifiers associated with the UE, the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like), the requested NSSAIfor the CAG, [mapping of (requested) NSSAI for the CAG], defaultconfigured NSSAI indication for one or more CAGs associated with thewireless device/UE, and/or the like.

In an example, the NG-RAN node may receive the one or more closed accessgroup identifiers associated with the UE, the closed access grouprestriction indicator (a CAG-only indication, a CAG-only UE indication,a cell mobility restriction for the UE, and/or the like, the requestedNSSAI for the CAG, [mapping of (requested) NSSAI for the CAG], defaultconfigured NSSAI indication for one or more CAGs associated with thewireless device/UE, and/or the like via RRC signaling. In an example, anRRC connection setup request message may be employed. In an example, anRRC connection establishment/re-establishment procedure may be employed.The RRC connection establishment procedure may comprise RRC connectionsetup request message, and/or the like. A capability IE within the RRCmessage, e.g., UE capability, RRC capability, and/or the like may beemployed to transmit the one or more closed access group identifiersassociated with the UE, the closed access group restriction indicator (aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like), the requested NSSAI for theCAG, [mapping of (requested) NSSAI for the CAG], default configuredNSSAI indication for one or more CAGs associated with the wirelessdevice/UE, and/or the like. In an example, the RRC connection setuprequest message (e.g., RRCSetupRequest, and/or the like) may comprisethe one or more closed access group identifiers associated with the UE,the closed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], default configured NSSAI indication for one or moreCAGs associated with the wireless device/UE, and/or the like.

In an example embodiment as depicted in FIG. 19, one or more RAN(NG-RAN) nodes may employ an Xn interface (e.g., Xn-C) to exchangeapplication level configuration data. In an example, an Xn setupprocedure may be employed. The Xn Setup procedure may be employed toexchange application level configuration data needed for two NG-RANnodes to interoperate correctly over the Xn-C interface. In an example,an NG-RAN node1 (e.g., Source NG-RAN) may initiate the procedure bysending an XN SETUP REQUEST message to a candidate NG-RAN node2 (TargetNG-RAN). The candidate NG-RAN node2 may reply with an XN SETUP RESPONSEmessage. If Supplementary uplink is configured at the NG-RAN node1, theNG-RAN node1 may include in the XN SETUP REQUEST message the SULInformation IE and the Supported SUL band List IE for each served cellwhere supplementary uplink is configured. If Supplementary Uplink isconfigured at the NG-RAN node2, the candidate NG-RAN node2 may includein the XN SETUP RESPONSE message the SUL Information IE and theSupported SUL band List IE for each served cell where supplementaryuplink is configured.

If the NG-RAN node1 is an ng-eNB, it may include the Protected E-UTRAResource Indication IE into the XN SETUP REQUEST. If the XN SETUPREQUEST sent by an ng-eNB comprises the Protected E-UTRA ResourceIndication IE, the receiving gNB may take this into account forcell-level resource coordination with the ng-eNB. The gNB may considerthe received Protected E-UTRA Resource Indication IE content valid untilreception of a new update of the IE for the same ng-eNB. The protectedresource pattern indicated in the Protected E-UTRA Resource IndicationIE may not be valid in subframes indicated by the Reserved Subframes IE,as well as in the non-control region of the MBSFN subframes e.g., it isvalid only in the control region therein. The size of the control regionof MBSFN subframes may be indicated in the Protected E-UTRA ResourceIndication IE.

In an example, the Xn setup request message may comprise a list ofclosed access group identifiers (CAG IDs) that one or more cells of theNG-RAN (e.g., target NG-RAN, Source NG-RAN, and/or the like) node maysupport. In an example, the Xn setup request may comprise: a messagetype, Global NG-RAN Node ID, TAI Support List, AMF Set Information, Listof Served Cells NR, Served Cell Information NR, Neighbour InformationNR, Neighbour Information E-UTRA, List of Served Cells E-UTRA, ServedCell Information E-UTRA, Neighbour Information NR, Neighbour InformationE-UTRA, and/or the like. In an example, Served Cell Information NR maycomprise NR-PCI, NR CGI, TAC, RANAC, Broadcast PLMNs, PLMN Identity,CHOICE NR-Mode-Info, FDD, FDD Info, UL NR Frequency Info, DL NRFrequency Info, UL transmission Bandwidth, DL Transmission Bandwidth,TDD, TDD Info, Frequency Info, Transmission Bandwidth, MeasurementTiming Configuration, Connectivity Support, and/or the like. In anexample, the Served Cell Information NR may comprise the list of closedaccess group identifiers (CAG IDs). In an example the Xn setup requestmessage may further comprise an information element (e.g.,maxnoofCellsinNG-RAN node) indicating a number of cells (e.g., Maximumnumber of cells) that may be served by a NG-RAN node.

In an example, the Xn setup request message may comprise a list ofclosed access group identifiers (CAG IDs) that one or more cells (e.g.,the CAG cells and/or non-CAG cells) of the NG-RAN (e.g., target NG-RAN,Source NG-RAN, and/or the like) node may support. In an example, the Xnsetup request message may further comprise one or more S-NSSAIs, allowedNSSAI, slice identifiers that the CAG cells and/or non-CAG cells of theRAN node, NG-RAN node, gNB node and/or the like may support.

In an example, the Xn setup response may comprise a Message Type, GlobalNG-RAN Node ID, TAI Support List, List of Served Cells NR, Served CellInformation NR, Neighbour Information NR, Neighbour Information E-UTRA,List of Served Cells E-UTRA, Served Cell Information E-UTRA, NeighbourInformation NR, Neighbour Information E-UTRA, Criticality Diagnostics,and/or the like. In an example, the Xn setup response message maycomprise a list of closed access group identifiers that one or morecells of the NG-RAN (e.g., target NG-RAN, Source NG-RAN, and/or thelike) node may support. In an example, the served cell information NRmay comprise the list of closed access group identifiers. In an examplethe Xn setup response message may further comprise an informationelement (e.g., maxnoofCellsinNG-RAN node) indicating a number of cells(e.g., Maximum number of cells) that may be served by a NG-RAN node.

In an example, the Xn setup response message may comprise a list ofclosed access group identifiers (CAG IDs) that one or more cells (theCAG cells and/or non-CAG cells) of the NG-RAN (e.g., target NG-RAN,Source NG-RAN, and/or the like) node may support. In an example, the Xnsetup response message may further comprise one or more S-NSSAIs,allowed NSSAI, slice identifiers that the CAG cells and/or non-CAG cellsof the RAN node, NG-RAN node, gNB node and/or the like may support.

In an example embodiment as depicted in FIG. 19, a RAN nodeconfiguration update, NG-RAN node configuration update, RAN contextupdate/exchange, and/or the like procedure may be employed. The NG-RANnode configuration update procedure may be employed to updateapplication level configuration data needed for two NG-RAN nodes tointeroperate correctly over the Xn, Xn-C, and/or the like interface. Inan example, the NG-RAN node1 may initiate the procedure by sending aNG-RAN NODE CONFIGURATION UPDATE message to a peer NG-RAN node2. IfSupplementary Uplink is configured at the NG-RAN node1, the NG-RAN node1may include in the NG-RAN NODE CONFIGURATION UPDATE message the SULInformation IE and the Supported SUL band List IE for each cell added inthe Served NR Cells To Add IE and in the Served NR Cells To Modify IE.If Supplementary Uplink is configured at the NG-RAN node2, the NG-RANnode2 may include in the NG-RAN NODE CONFIGURATION UPDATE ACKNOWLEDGEmessage the SUL Information IE and the Supported SUL band List IE foreach cell added in the Served NR Cells IE if any. If the TAI SupportList IE is included in the NG-RAN NODE CONFIGURATION UPDATE message, thereceiving node may replace the previously provided TAI Support List IEby the received TAI Support List IE. If the Cell Assistance InformationNR IE is present, the NG-RAN node2 may use it to generate the Served NRCells IE and include the list in the NG-RAN NODE CONFIGURATION UPDATEACKNOWLEDGE message.

In an example, the NG-RAN NODE CONFIGURATION UPDATE message and/or theCONFIGURATION UPDATE ACKNOWLEDGE message may comprise a list of closedaccess group identifiers (CAG IDs) that one or more cells (e.g., the CAGcells and/or non-CAG cells) of the NG-RAN (e.g., target NG-RAN, SourceNG-RAN, and/or the like) node may support. In an example, the NG-RANNODE CONFIGURATION UPDATE message may further comprise one or moreS-NSSAIs, allowed NSSAI, slice identifiers that the CAG cells and/ornon-CAG cells of the RAN node, NG-RAN node, gNB node and/or the like maysupport.

In an example, upon reception of the NG-RAN NODE CONFIGURATION UPDATEmessage, NG-RAN node2 may update the Served Cell Information NR. IfServed Cells NR To Add IE is contained in the NG-RAN NODE CONFIGURATIONUPDATE message, NG-RAN node2 may add cell information according to theinformation in the Served Cell Information NR IE. If Served Cells NR ToModify IE is contained in the NG-RAN NODE CONFIGURATION UPDATE message,NG-RAN node2 may modify information of cell indicated by Old NR-CGI IEaccording to the information in the Served Cell Information NR IE. Wheneither served cell information or neighbour information of an existingserved cell in NG-RAN node1 need to be updated, the whole list ofneighbouring cells, if any, may be contained in the NeighbourInformation NR IE. The NG-RAN node2 may overwrite the served cellinformation and the whole list of neighbour cell information for theaffected served cell. If the Deactivation Indication IE is contained inthe Served Cells NR To Modify IE, it may indicate that the concernedcell was switched off to lower energy consumption. If Served Cells NR ToDelete IE is contained in the NG-RAN NODE CONFIGURATION UPDATE message,NG-RAN node2 may delete information of cell indicated by Old NR-CGI IE.

In an example, upon reception of the NG-RAN NODE CONFIGURATION UPDATEmessage, NG-RAN node2 may update Served Cell Information E-UTRA. IfServed Cells E-UTRA To Add IE is contained in the NG-RAN NODECONFIGURATION UPDATE message, NG-RAN node2 may add cell informationaccording to the information in the Served Cell Information E-UTRA IE.If Served Cells E-UTRA To Modify IE is contained in the NG-RAN NODECONFIGURATION UPDATE message, NG-RAN node2 may modify information ofcell indicated by Old ECGI IE according to the information in the ServedCell Information E-UTRA IE. When either served cell information orneighbour information of an existing served cell in NG-RAN node1 need tobe updated, the whole list of neighbouring cells, if any, may becontained in the Neighbour Information E-UTRA IE. The NG-RAN node2 mayoverwrite the served cell information and the whole list of neighbourcell information for the affected served cell. If the DeactivationIndication IE is contained in the Served Cells E-UTRA To Modify IE, itmay indicate that the concerned cell was switched off to lower energyconsumption. If the Served Cells E-UTRA To Delete IE is contained in theNG-RAN NODE CONFIGURATION UPDATE message, NG-RAN node2 may deleteinformation of cell indicated by Old ECGI IE. If the Protected E-UTRAResource Indication IE is included into the NG-RAN NODE CONFIGURATIONUPDATE (inside the Served Cell Information E-UTRA IE), the receiving gNBmay take this into account for cell-level resource coordination with theng-eNB. The gNB may consider the received Protected E-UTRA ResourceIndication IE content valid until reception of a new update of the IEfor the same ng-eNB. The protected resource pattern indicated in theProtected E-UTRA Resource Indication IE may not be valid in subframesindicated by the Reserved Subframes IE (contained in E-UTRA NR CELLRESOURCE COORDINATION REQUEST messages), as well as in the non-controlregion of the MBSFN subframes e.g., it may be valid in the controlregion therein. The size of the control region of MBSFN subframes may beindicated in the Protected E-UTRA Resource Indication IE.

In an example, upon reception of the NG-RAN NODE CONFIGURATION UPDATEmessage, NG-RAN node2 may update TNL addresses for SCTP associations. Ifthe TNL Association to Add List IE is included in the NG-RAN NODECONFIGURATION UPDATE message, the NG-RAN node2 may, if supported, use itto establish the TNL association(s) with the NG-RAN node1. The NG-RANnode2 may report to the NG-RAN node1, in the NG-RAN NODE CONFIGURATIONUPDATE ACKNOWLEDGE message, the successful establishment of the TNLassociation(s) with the NG-RAN node as follows: A list of successfullyestablished TNL associations shall be included in the TNL AssociationSetup List IE, a list of TNL associations that failed to be establishedshall be included in the TNL Association Failed to Setup List IE. In anexample, if the TNL Association to Remove List IE is included in theNG-RAN NODE CONFIGURATION UPDATE message the NG-RAN node2 may, ifsupported, initiate removal of the TNL association(s) indicated by thereceived Transport Layer information towards the NG-RAN node1. If theTNL Association to Update List IE is included in the NG-RAN NODECONFIGURATION UPDATE message the NG-RAN node2 may, if supported, updatethe TNL association(s) indicated by the received Transport Layerinformation towards the NG-RAN node1.

In an example embodiment, the NG-RAN NODE CONFIGURATION UPDATE messagemay comprise a list of closed access group identifiers (CAG IDs) thatone or more cells of the NG-RAN (e.g., target NG-RAN, Source NG-RAN,and/or the like) node may support. In an example, the served cellinformation NR may comprise the list of closed access group identifiers.

In an example embodiment as depicted in FIG. 17 and FIG. 20, handoverprocedures may be performed. The handover procedures may be employed tohand over the UE from a source NG-RAN node to a target NG-RAN node usingthe Xn or N2 reference points. The handover procedures may be triggered,for example, due to new radio conditions, load balancing, due tospecific service e.g. in the presence of QoS Flow for voice, and/or thelike, the source NG-RAN node being NR may trigger handover to E-UTRA ora different NR NG-RAN connected to 5GC and vice versa.

In an example embodiment, during the Xn setup procedure and/orconfiguration update procedure, the RAN/NG-RAN nodes may employ the listof closed access group identifiers (CAG IDs) that one or more cells(e.g., the CAG cells and/or non-CAG cells) of the NG-RAN (e.g., targetNG-RAN, Source NG-RAN, and/or the like) node may support, the one ormore S-NSSAIs, allowed NSSAI, slice identifiers that the CAG cellsand/or non-CAG cells of the RAN node, NG-RAN node, gNB node and/or thelike may support, to determine whether to accept or reject a handoverrequest (e.g., from a RAN node, a UE, AMF, and/or the like), select atarget RAN node for handover of the UE, and/or the like.

In an example embodiment, a handover preparation procedure may beemployed to request the preparation of resources at the target side viathe 5GC. In an example, a source NG-RAN node may initiate a handoverpreparation by sending the HANDOVER REQUIRED message to a serving AMF.When the source NG-RAN node sends the HANDOVER REQUIRED message, it maystart a timer e.g., TNGRELOCprep, and/or the like. The source NG-RANnode may indicate the appropriate cause value for the handover in theCause IE. Upon reception of the HANDOVER REQUIRED message the AMF may,for each PDU session indicated in the PDU Session ID IE, transparentlytransfer the Handover Required Transfer IE to the SMF associated withthe concerned PDU session(s). In case of intra-system handover, theinformation in the Source to Target Transparent Container IE may beencoded according to the definition of the Source NG-RAN node to TargetNG-RAN node Transparent Container IE. If the DL Forwarding IE isincluded for a given QoS flow in the PDU Session Resource InformationItem IE within the Source NG-RAN node to Target NG-RAN node TransparentContainer IE of the HANDOVER REQUIRED message and it is set to “DLforwarding proposed”, it may indicate that the source NG-RAN nodeproposes forwarding of downlink data for that QoS flow. If the DRBs toQoS Flows Mapping List IE is included in the PDU Session ResourceInformation Item IE within the Source NG-RAN node to Target NG-RAN nodeTransparent Container IE of the HANDOVER REQUIRED message, it mayindicates that the source NG-RAN node proposes forwarding of downlinkdata for those DRBs. If the QoS Flow Mapping Indication IE for a QoSflow is included in the Associated QoS Flow List IE within the DRBs toQoS Flows Mapping List IE within the Source NG-RAN node to Target NG-RANnode Transparent Container IE of the HANDOVER REQUIRED message, it mayindicate that the source NG-RAN node has mapped the uplink or downlinkof the QoS flow to the DRB. If the HANDOVER COMMAND message contains theDL Forwarding UP TNL Information IE for a given DRB within the HandoverCommand Transfer IE, the source NG-RAN node may consider that theforwarding of downlink data for this DRB is accepted by the targetNG-RAN node. If the HANDOVER COMMAND message contains the UL ForwardingUP TNL Information IE for a given DRB in the Data Forwarding ResponseDRB List IE within the Handover Command Transfer IE, it means the targetNG-RAN node has requested the forwarding of uplink data for this DRB.

In an example, in case of inter-system handover to LTE, the informationin the Source to Target Transparent Container IE may be encodedaccording to the Source eNB to Target eNB Transparent Container IE. Whenthe preparation, including the reservation of resources at the targetside is ready, the AMF may respond with the HANDOVER COMMAND message tothe source NG-RAN node. Upon reception of the HANDOVER COMMAND messagethe source NG-RAN node may stop the timer TNGRELOCprep and start thetimer TNGRELOCoverall.

If there are any PDU Sessions that could not be admitted in the target,they may be indicated in the PDU Session Resources to Release List IE.If the HANDOVER COMMAND message contains the QoS Flow to be ForwardedList IE within the Handover Command Transfer IE for a given PDU session,then the source NG-RAN node may initiate data forwarding for the listedQoS flows. If the Target to Source Transparent Container IE has beenreceived by the AMF from the handover target then the transparentcontainer may be included in the HANDOVER COMMAND message. If the Indexto RAT/Frequency Selection Priority IE is contained in the Source NG-RANNode to Target NG-RAN Node Transparent Container IE, the target NG-RANnode may store the content of the received Index to RAT/FrequencySelection Priority IE in the UE context.

In an example, interactions with other NGAP procedures may comprise thefollowing. If, after a HANDOVER REQUIRED message is sent and before theHandover Preparation procedure is terminated, the source NG-RAN nodereceives an AMF initiated PDU Session Management procedure on the sameUE-associated signalling connection, the source NG-RAN node may cancelthe handover preparation procedure by executing the handovercancellation procedure with an appropriate cause value. After successfulcompletion of the Handover Cancellation procedure, the source NG-RANnode may continue the AMF initiated PDU Session Management procedure. Inan example, the source NG-RAN node may terminate the AMF initiated PDUSession Management procedure by sending the appropriate response messagewith an appropriate cause value, e.g. “NG intra-system handovertriggered” or “NG inter-system handover triggered” to the AMF and thenthe source NG-RAN node may continue with the handover procedure.

In an example, if the 5GC or the target side is not able to accept anyof the PDU session resources or a failure occurs during the HandoverPreparation, the AMF may send a HANDOVER PREPARATION FAILURE messagewith an appropriate cause value to the source NG-RAN node. If there isno response from the AMF to the HANDOVER REQUIRED message before timerTNGRELOCprep expires in the source NG-RAN node, the source NG-RAN nodemay cancel the Handover Preparation procedure by initiating the HandoverCancel procedure with the appropriate value for the Cause IE. The sourceNG-RAN node may ignore any HANDOVER COMMAND message or HANDOVERPREPARATION FAILURE message received after the initiation of theHandover Cancel procedure.

In an example, if the NG-RAN node receives at least one PDU Session IDincluded in the PDU Session Resource Handover List IE without at leastone valid associated GTP tunnel address pair (in either UL or DL), thenthe NG-RAN node may consider it as a logical error. A GTP tunnel addresspair may be considered valid if both the GTP-TEID IE and the Endpoint IPAddress IE are present.

In an example, a handover resource allocation procedure may be employedto reserve resources at the target NG-RAN node for the handover of theUE. In an example the AMF may initiate the procedure by sending theHANDOVER REQUEST message to the target NG-RAN node. If the Masked IMEISVIE is contained in the HANDOVER REQUEST message the target NG-RAN nodemay, if supported, use it to determine the characteristics of the UE forsubsequent handling. Upon receipt of the HANDOVER REQUEST message thetarget NG-RAN node may attempt to execute the requested PDU sessionconfiguration and associated security, store the UE Aggregate MaximumBit Rate in the UE context, and use the received UE Aggregate MaximumBit Rate for all non-GBR QoS flows for the concerned UE, store thereceived Mobility Restriction List in the UE context, store the receivedUE Security Capabilities in the UE context, store the received SecurityContext in the UE context, and/or the like.

Upon reception of the UE History Information IE, which is includedwithin the Source to Target Transparent Container IE of the HANDOVERREQUEST message, the target NG-RAN node may collect the informationdefined as mandatory in the UE History Information IE and may, ifsupported, collect the information defined as optional in the UE HistoryInformation IE, for as long as the UE stays in one of its cells, andstore the collected information to be used for future handoverpreparations. Upon receiving the PDU Session Resource Setup List IEcontained in the HANDOVER REQUEST message, the target NG-RAN node maybehave the same as defined in the PDU Session Resource Setup procedure.The target NG-RAN node may report to the AMF in the HANDOVER REQUESTACKNOWLEDGE message the result for each PDU session resource requestedto be setup. In particular, for each PDU session resource successfullysetup, it may include the Handover Request Acknowledge Transfer IE thatmay comprise the list of QoS flows which have been successfullyestablished in the QoS Flow Setup Response List IE, the Data ForwardingAccepted IE if the data forwarding for the QoS flow is accepted, thelist of QoS flows which have failed to be established, if any, in theQoS Flow Failed to Setup List IE, the UP transport layer information tobe used for the PDU session, the security result associated to the PDUsession, and/or the like.

In an example, for one or more PDU session resource which failed to besetup, the Handover Resource Allocation Unsuccessful Transfer IE may beincluded in the HANDOVER REQUEST ACKNOWLEDGE message containing a causevalue that should be precise enough to enable the SMF to know the reasonfor the unsuccessful establishment. Upon reception of the HANDOVERREQUEST ACKNOWLEDGE message the AMF may, for each PDU session indicatedin the PDU Session ID IE, transfer transparently the Handover RequestAcknowledge Transfer IE or Handover Resource Allocation UnsuccessfulTransfer IE to the SMF associated with the concerned PDU session. If theHANDOVER REQUEST message contains the Data Forwarding Not Possible IEassociated with a given PDU session within the Handover Request TransferIE set to “data forwarding not possible”, the target NG-RAN node may notinclude the DL Forwarding UP TNL Information IE and for intra-systemhandover the Data Forwarding Response DRB List IE within the HandoverRequest Acknowledge Transfer IE in the HANDOVER REQUEST ACKNOWLEDGEmessage for that PDU session. In case of intra-system handover, if thetarget NG-RAN node accepts the downlink data forwarding for at least oneQoS flow for which the DL Forwarding IE is set to “DL forwardingproposed”, it may include the DL Forwarding UP TNL Information IE in theHandover Request Acknowledge Transfer IE for the PDU session within thePDU Session Resource Admitted List IE of the HANDOVER REQUESTACKNOWLEDGE message. In case of intra-system handover, if the targetNG-RAN node accepts the data forwarding for a successfully configuredDRB, the target NG-RAN node may include the DL Forwarding UP TNLInformation IE for the DRB within the Data Forwarding Response DRB ListIE within Handover Request Acknowledge Transfer IE of the HANDOVERREQUEST ACKNOWLEDGE message. If the HANDOVER REQUEST ACKNOWLEDGE messagecontains the UL Forwarding UP TNL Information IE for a given DRB in theData Forwarding Response DRB List IE within the Handover RequestAcknowledge Transfer IE, it may indicate the target NG-RAN node hasrequested the forwarding of uplink data for the DRB.

In case of inter-system handover from E-UTRAN, the target NG-RAN nodemay include the Data Forwarding Accepted IE for each QoS flow that theDL Forwarding IE is set to “DL forwarding proposed” for thecorresponding E-RAB in the Source NG-RAN Node to Target NG-RAN NodeTransparent Container IE and that the target NG-RAN node has admittedthe proposed forwarding of downlink data for the QoS flow. If the targetNG-RAN node accepts the downlink data forwarding for at least one QoSflow of an admitted PDU session it may include the DL Forwarding UP TNLInformation IE in the PDU Session Resource Setup Response Transfer IEfor that PDU session within the PDU Session Resources Admitted List IEof the HANDOVER REQUEST ACKNOWLEDGE message. The target NG-RAN node mayemploy the information in the Mobility Restriction List IE if present inthe HANDOVER REQUEST message to determine a target for subsequentmobility action for which the target NG-RAN node provides informationabout the target of the mobility action towards the UE, select a properSCG during dual connectivity operation, assign proper RNA(s) for the UEwhen moving the UE to RRC_INACTIVE state, and/or the like. If theMobility Restriction List IE is not contained in the HANDOVER REQUESTmessage, the target NG-RAN node may consider that no roaming and noaccess restriction may apply to the UE. The target NG-RAN node mayconsider that no roaming and no access restriction apply to the UE whenone of the QoS flows includes a particular ARP value. If the TraceActivation IE is included in the HANDOVER REQUEST message the targetNG-RAN node may, if supported, initiate the requested trace function.

In an example, if the Location Reporting Request Type IE is included inthe HANDOVER REQUEST message, the target NG-RAN node may perform therequested location reporting functionality for the UE. If the CoreNetwork Assistance Information IE is included in the HANDOVER REQUESTmessage, the target NG-RAN node may, if supported, store thisinformation in the UE context and use it for e.g. the RRC_INACTIVE statedecision and RNA configuration for the UE and RAN paging if any for a UEin RRC_INACTIVE state, and/or the like. If the RRC Inactive TransitionReport Request IE is included in the HANDOVER REQUEST message, theNG-RAN node may, if supported, store this information in the UE context.After all necessary resources for the admitted PDU session resourceshave been allocated, the target NG-RAN node may generate the HANDOVERREQUEST ACKNOWLEDGE message.

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise one or more closed access group identifiersassociated with the UE.

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like).

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise the requested NSSAI for the CAG, [mappingof (requested) NSSAI for the CAG], default configured NSSAI indicationfor one or more CAGs associated with the wireless device/UE, and/or thelike.

In an example embodiment, the source NG-RAN node may receive one or moreclosed access group identifiers associated with the UE, that maycomprise the closed access group restriction indicator, the requestedNSSAI for the CAG, and/or the like via an RRC message. The source NG-RANnode may determine the target NG-RAN node based on the one or moreclosed access group identifiers associated with the UE, the closedaccess group restriction indicator, the requested NSSAI for the CAG,and/or the like. In an example, the AMF may receive the one or moreclosed access group identifiers associated with the UE, the closedaccess group restriction indicator, the requested NSSAI for the CAG,and/or the like from the sources NG-RAN node and may employ theinformation to determine the target NG-RAN node or whether the targetNG-RAN node may serve the UE. If the closed access group restrictionindicator indicates that the UE is restricted to CAG cells, and the CAGID associated with the UE does not match with one or more CAG IDs servedby the target NG-RAN node, the AMF may notify with a failure indication,handover failure message, and/or like with an error/rejection cause IE.

In an example, the target NG-RAN node may send a HANDOVER NOTIFY messageto the AMF when the UE has been identified in the target cell and theNG-based handover has been successfully completed.

In an example, a path switch request procedure may be employed torequest the switch of the downlink termination point of the NG-Utransport bearer towards a new termination point. The NG-RAN node mayinitiate the procedure by sending the PATH SWITCH REQUEST message to theAMF. Upon reception of the PATH SWITCH REQUEST message the AMF may, foreach PDU session indicated in the PDU Session ID IE, transparentlytransfer the Path Switch Request Transfer IE to the SMF associated withthe concerned PDU session. After one or more necessary updates includingthe UP path switch have been successfully completed in the 5GC for atleast one of the PDU session resources included in the PATH SWITCHREQUEST, the AMF may send the PATH SWITCH REQUEST ACKNOWLEDGE message tothe NG-RAN node. The list of accepted QoS flows may be included in thePATH SWITCH REQUEST message within the Path Switch Request Transfer IE.The list of PDU sessions which failed to be setup, if any, may beincluded in the PATH SWITCH REQUEST message within the Path SwitchRequest Setup Failed Transfer IE. For each PDU session for which theUser Plane Security Information IE is included in the Path SwitchRequest Transfer IE of the PATH SWITCH REQUEST message, the SMF may sendback the Security Indication IE within the Path Switch RequestAcknowledge Transfer IE of the PATH SWITCH REQUEST ACKNOWLEDGE message.For each PDU session for which the DL NG-U TNL Information Reused IE setto “true” is included in the Path Switch Request Transfer IE of the PATHSWITCH REQUEST message, the SMF may, if supported, consider that the DLTNL information contained in the DL NG-U UP TNL Information IE has beenreused. If the UL NG-U UP TNL Information IE is included within the PathSwitch Request Acknowledge Transfer IE of the PATH SWITCH REQUESTACKNOWLEDGE message, the NG-RAN node may store this information and useit as the uplink termination point for the user plane data for this PDUsession. if the core network assistance information IE is included inthe PATH SWITCH REQUEST ACKNOWLEDGE message, the NG-RAN node may, ifsupported, store this information in the UE context and use it for e.g.,the RRC_INACTIVE state decision and RNA configuration for the UE and RANpaging if any for a UE in RRC_INACTIVE state. If the RRC InactiveTransition Report Request IE is included in the PATH SWITCH REQUESTACKNOWLEDGE message, the NG-RAN node may, if supported, store thisinformation in the UE context. Upon reception of the PATH SWITCH REQUESTACKNOWLEDGE message the NG-RAN node may store the received SecurityContext IE in the UE context. If the PDU Session Resource Released ListIE is included in the PATH SWITCH REQUEST ACKNOWLEDGE message, theNG-RAN node may release the corresponding QoS flows and regard the PDUsession(s) indicated in the PDU Session Resource Released List IE asbeing released. The appropriate cause value for each PDU sessionreleased may be included in the path switch request unsuccessfultransfer IE contained in the PATH SWITCH REQUEST ACKNOWLEDGE message.

In an example, a handover cancellation procedure may be employed toenable a source NG-RAN node to cancel an ongoing handover preparation oran already prepared handover.

In an example, an Uplink RAN Status Transfer procedure may be employedto enable lossless NG-based handover. The source NG-RAN node mayinitiate the procedure by stopping the assigning of PDCP-SNs to downlinkSDUs and sending the UPLINK RAN STATUS TRANSFER message to the AMF atthe point in time when it considers the transmitter/receiver status tobe frozen. For one or more DRB for which PDCP-SN and HFN statuspreservation applies, the source NG-RAN node may include the DRB ID IE,the UL COUNT Value IE and the DL COUNT Value IE within the DRBs Subjectto Status Transfer List IE in the RAN Status Transfer TransparentContainer IE of the UPLINK RAN STATUS TRANSFER message. The sourceNG-RAN node may include in the UPLINK RAN STATUS TRANSFER message themissing and the received uplink SDUs in the Receive Status of UL PDCPSDUs IE for each DRB for which the source NG-RAN node has accepted therequest from the target NG-RAN node for uplink forwarding.

In an example, a Downlink RAN Status Transfer procedure may be employedto enable lossless NG-based handover. The AMF may initiate the procedureby sending the DOWNLINK RAN STATUS TRANSFER message to the target NG-RANnode. The target NG-RAN node using Full Configuration for this handovermay ignore the information received in this message. For one or more DRBin the DRBs Subject to Status Transfer List IE within the RAN StatusTransfer Transparent Container IE, the target NG-RAN node may notdeliver any uplink packet which has a PDCP-SN lower than the value ofthe UL Count Value IE. For one or more DRB in the DRBs Subject to StatusTransfer List IE within the RAN Status Transfer Transparent ContainerIE, the target NG-RAN node may employ the value of the DL COUNT Value IEfor the first downlink packet for which there is no PDCP-SN yetassigned. If the Receive Status of UL PDCP SDUs IE is included for atleast one DRB in the RAN Status Transfer Transparent Container IE of theDOWNLINK RAN STATUS TRANSFER message, the target NG-RAN node may use itin a Status Report message sent to the UE over the radio interface.

In an example embodiment, the handover request message, and/or the likemay comprise one or more closed access group identifiers associated withthe UE.

In an example embodiment, the handover request message, and/or the likemay comprise the closed access group restriction indicator (a CAG-onlyindication, a CAG-only UE indication, a cell mobility restriction forthe UE, and/or the like).

In an example embodiment, the handover request message, and/or the likemay comprise the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], default configured NSSAI indication for one or moreCAGs associated with the wireless device/UE, and/or the like.

In an example embodiment, mobility procedures may be employed toestablish necessary resources in an NG-RAN node. In an example, thesource NG-RAN node may initiate the procedure by sending the HANDOVERREQUEST message to the target NG-RAN node. When the source NG-RAN nodesends the HANDOVER REQUEST message, it may start a timer (e.g.,TXnRELOCprep). For one or more E-RAB ID IE included in the QoS Flow ToBe Setup List IE in the HANDOVER REQUEST message, the target NG-RAN nodemay, if supported, store the content of the IE in the UE context and useit for subsequent inter-system handover. If the Masked IMEISV IE iscontained in the HANDOVER REQUEST message the target NG-RAN node may, ifsupported, use it to determine the characteristics of the UE forsubsequent handling. At reception of the HANDOVER REQUEST message thetarget NG-RAN node may prepare the configuration of the AS securityrelation between the UE and the target NG-RAN node by using theinformation in the UE Security Capabilities IE and the AS SecurityInformation IE in the UE Context Information IE. The target NG-RAN nodemay report in the HANDOVER REQUEST ACKNOWLEDGE message the successfulestablishment of the result for all the requested PDU session resources.When the target NG-RAN node reports the unsuccessful establishment of aPDU session resource, the cause value may be precise enough to enablethe source NG-RAN node to know the reason for the unsuccessfulestablishment. For one or more PDU session(s) if the PDU SessionAggregate Maximum Bit Rate IE is included in the PDU Session ResourcesTo Be Setup List IE contained in the HANDOVER REQUEST message, thetarget NG-RAN node may store the received PDU Session Aggregate MaximumBit Rate in the UE context and use it when enforcing traffic policingfor non-GBR QoS flows for the concerned UE. For one or more QoS flow(s)for which the source NG-RAN node proposes to perform forwarding ofdownlink data, the source NG-RAN node may include the DL Forwarding IEset to “DL forwarding proposed” within the QoS Flows To Be Setup List IEin the PDU Session Resource To Be Setup List IE in the HANDOVER REQUESTmessage. For each PDU session that the target NG-RAN node decides toadmit the data forwarding for at least one QoS flow, the target NG-RANnode may include the PDU Session level DL data forwarding GTP-U TunnelEndpoint IE within the Data Forwarding Info from target NG-RAN node IEin the PDU Session Admitted Response Transfer IE contained in the PDUSessions Admitted List IE in the HANDOVER REQUEST ACKNOWLEDGE message.For one or more DRB(s) for which the source NG-RAN node proposes toperform forwarding of downlink data, the source NG-RAN node may includethe DRB ID IE and the mapped QoS Flows List IE within the Source DRB toQoS Flow Mapping List IE contained in the PDU Session Resources To BeSetup List IE in the HANDOVER REQUEST message. The source NG-RAN nodemay include the QoS Flow Mapping Indication IE in the Source DRB to QoSFlow Mapping List IE to indicate that the uplink or downlink QoS flow ismapped to the DRB. If the target NG-RAN node decides to use the same DRBconfiguration and to map the same QoS flows as the source NG-RAN node,the target NG-RAN node may include the DL Forwarding GTP Tunnel EndpointIE within the Data Forwarding Response DRB List IE in the HANDOVERREQUEST ACKNOWLEDGE message to indicate that it accepts the proposedforwarding of downlink data for this DRB. If the HANDOVER REQUESTACKNOWLEDGE message contains the UL Forwarding GTP Tunnel Endpoint IEfor a given DRB in the Data Forwarding Response DRB List IE within DataForwarding Info from target NG-RAN node IE in the PDU Session ResourcesAdmitted List IE and the source NG-RAN node accepts the data forwardingproposed by the target NG-RAN node, the source NG-RAN node may performforwarding of uplink data for the DRB. If the HANDOVER REQUEST includesPDU session resources for PDU sessions associated to S-NSSAIs notsupported by target NG-RAN, the target NG-RAN may reject such PDUsession resources. In this case, and if at least one PDU SessionResource To Be Setup Item IE is admitted, the target NG-RAN may send theHANDOVER REQUEST ACKNOWLEDGE message including the PDU Session ResourcesNot Admitted List IE listing corresponding PDU sessions rejected at thetarget NG-RAN. If the Mobility Restriction List IE is contained in theHANDOVER REQUEST message, the target NG-RAN node may store theinformation received in the Mobility Restriction List IE in the UEcontext, use this information to determine a target for the UE duringsubsequent mobility action for which the NG-RAN node providesinformation about the target of the mobility action towards the UE,except when one of the PDU sessions has a particular ARP value in whichcase the information shall not apply, use this information to select aproper SCG during dual connectivity operation, use this information toselect proper RNA(s) for the UE when moving the UE to RRC_INACTIVE,and/or the like.

In an example embodiment, the handover request message sent from thesource NG-RAN node to the target NG-RAN node, and/or the like maycomprise one or more closed access group identifiers (CAG IDs)associated with the UE.

In an example embodiment, the handover request message may comprise theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like).

In an example embodiment, the handover request message may comprise therequested NSSAI for the CAG, [mapping of (requested) NSSAI for the CAG],default configured NSSAI indication for one or more CAGs associated withthe wireless device/UE, and/or the like.

In an example embodiment, the Mobility Restriction List IE may comprisethe closed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), one or more CAG IDs that the UE is allowed to access, one ormore S-NSSAIs per CAG or a mapping of allowed NSSAIs for the CAG, and/orthe like.

In an example embodiment, the source NG-RAN node may employ the CAG IDs,the closed access group restriction indicator, mapping of (requested)NSSAI for the CAG, and/or the like to select the target NG-RAN forhandover of the UE. In an example, the target NG-RAN may employ the CAGIDs, the closed access group restriction indicator, mapping of(requested) NSSAI for the CAG, and/or the like to determine whether toaccept or reject the handover request. For example, if the UE isrestricted to CAG cells and not allowed to access via non-CAG cells andthe target NG-RAN does not serve/support the CAG IDs associated with theUE, the handover request may be rejected.

If the Mobility Restriction List IE is not contained in the HANDOVERREQUEST message, the target NG-RAN node may consider that no roaming andno access restriction may apply to the UE.

In an example, if the Trace Activation IE is included in the HANDOVERREQUEST message the target NG-RAN node may, if supported, initiate therequested trace function. If the Index to RAT/Frequency SelectionPriority IE is contained in the HANDOVER REQUEST message, the targetNG-RAN node may store this information. For each PDU session, if theNetwork Instance IE is included in the PDU Session Resource To Be SetupList IE, the target NG-RAN node may, if supported, use it when selectingtransport network resource.

For each PDU session for which the Security Indication IE is included inthe PDU Session Resource To Be Setup List IE and the IntegrityProtection Indication IE or Confidentiality Protection Indication IE isset to “required”, the target NG-RAN node may perform user planeintegrity protection or ciphering, respectively. If the NG-RAN node isnot able to perform the user plane integrity protection or ciphering, itmay reject the setup of the PDU Session Resources with an appropriatecause value. If the NG-RAN node is an ng-eNB, it may reject all PDUsessions for which the Integrity Protection Indication IE is set to“required”.

For each PDU session for which the Security Indication IE is included inthe PDU Session Resource To Be Setup List IE and the IntegrityProtection Indication IE or the Confidentiality Protection Indication IEis set to “preferred”, the target NG-RAN node may, if supported, performuser plane integrity protection or ciphering, respectively and shallnotify the SMF whether it succeeded the user plane integrity protectionor ciphering or not for the concerned security policy.

For each PDU session for which the Maximum Integrity Protected Data RateIE is included in the Security Indication IE in the PDU SessionResources To Be Setup List IE, the NG-RAN node may store the respectiveinformation and, if integrity protection is to be performed for the PDUsession, it may enforce the traffic corresponding to the receivedMaximum Integrity Protected Data Rate IE, for the concerned PDU sessionand concerned UE.

For each PDU session for which the Security Indication IE is included inthe PDU Session Resource To Be Setup List IE and the IntegrityProtection Indication IE or Confidentiality Protection Indication IE isset to “not needed”, the target NG-RAN node may not perform user planeintegrity protection or ciphering, respectively, for the concerned PDUsession

If the Location Reporting Information IE is included in the HANDOVERREQUEST message, then the target NG-RAN node should initiate therequested location reporting functionality. Upon reception of UE HistoryInformation IE in the HANDOVER REQUEST message, the target NG-RAN nodemay collect the information defined as mandatory in the UE HistoryInformation IE and shall, if supported, collect the information definedas optional in the UE History Information IE, for as long as the UEstays in one of its cells, and store the collected information to beused for future handover preparations.

In an example embodiment, if the target NG-RAN node does not admit atleast one PDU session resource, or a failure occurs during the HandoverPreparation, the target NG-RAN node may send the HANDOVER PREPARATIONFAILURE message to the source NG-RAN node. The message may contain theCause IE with an appropriate value. If there is no response from thetarget NG-RAN node to the HANDOVER REQUEST message before timerTXnRELOCprep expires in the source NG-RAN node, the source NG-RAN nodemay cancel the Handover Preparation procedure towards the target NG-RANnode by initiating the Handover Cancel procedure with the appropriatevalue for the Cause IE. The source NG-RAN node may ignore any HANDOVERREQUEST ACKNOWLEDGE or HANDOVER PREPARATION FAILURE message receivedafter the initiation of the Handover Cancel procedure and remove anyreference and release any resources related to the concerned XnUE-associated signalling.

In an example embodiment, if the supported algorithms for encryptiondefined in the UE Security Capabilities IE in the UE Context InformationIE, plus the mandated support of the EEAO and NEAO algorithms in all UEsdo not match any allowed algorithms defined in the configured list ofallowed encryption algorithms in the NG-RAN node, the NG-RAN node mayreject the procedure using the HANDOVER PREPARATION FAILURE message.

In an example, SN Status Transfer procedure may be employed to transferthe uplink PDCP SN and HFN receiver status and the downlink PDCP SN andHFN transmitter status either, from the source to the target NG-RAN nodeduring an Xn handover, or between the NG-RAN nodes involved in dualconnectivity, for each respective DRB of the source DRB configurationfor which PDCP SN and HFN status preservation applies. In an example,the source NG-RAN node may initiate the procedure by stop assigning PDCPSNs to downlink SDUs and stop delivering UL SDUs towards the 5GC andsending the SN STATUS TRANSFER message to the target NG-RAN node at thetime point when it considers the transmitter/receiver status to befrozen. The target NG-RAN node using full configuration for thishandover may ignore the information received in this message. For eachDRB for which PDCP-SN and HFN status preservation applies, the sourceNG-RAN node may include the DRB ID IE, the UL COUNT Value IE and the DLCOUNT Value IE within the DRBs Subject to Status Transfer List IE in theSN STATUS TRANSFER message. The source NG-RAN node may include in the SNSTATUS TRANSFER message the missing and the received uplink SDUs in theReceive Status of UL PDCP SDUs IE for each DRB for which the sourceNG-RAN node has accepted the request from the target NG-RAN node foruplink forwarding. For each DRB in the DRBs Subject to Status TransferList IE, the target NG-RAN node may not deliver any uplink packet whichhas a PDCP-SN lower than the value contained within the UL Count ValueIE. For each DRB in the DRBs Subject to Status Transfer List IE, thetarget NG-RAN node may use the value of the PDCP SN contained within theDL COUNT Value IE for the first downlink packet for which there is noPDCP-SN yet assigned. If the Receive Status of UL PDCP SDUs IE isincluded for at least one DRB in the SN STATUS TRANSFER message, thetarget NG-RAN node may use it in a Status Report message sent to the UEover the radio interface.

In an example embodiment, a handover cancel procedure may be employed toenable a source NG-RAN node to cancel an ongoing handover preparation oran already prepared handover. The source NG-RAN node may initiate theprocedure by sending the HANDOVER CANCEL message to the target NG-RANnode. The source NG-RAN node may indicate the reason for cancelling thehandover by means of an appropriate cause value.

In an example embodiment, a retrieve ue context procedure may beemployed. The Retrieve UE Context procedure may be employed to retrievethe UE context from the old NG-RAN node and transfer it to the NG-RANnode where the UE RRC Connection has been requested to be established,and/or to enable the old NG-RAN node to forward an RRC message to the UEvia the new NG-RAN node without context transfer.

The new NG-RAN node may initiate the procedure by sending the RETRIEVEUE CONTEXT REQUEST message to the old NG-RAN node. If the old NG-RANnode is able to identify the UE context by means of the UE Context ID,and to successfully verify the UE by means of the integrity protectioncontained in the RETRIEVE UE CONTEXT REQUEST message, and decides toprovide the UE context to the new NG-RAN node, it may respond to the newNG-RAN node with the RETRIEVE UE CONTEXT RESPONSE message. If the oldNG-RAN node determines/decides to keep the UE context in case ofperiodic RNAU, it may store the Allocated C-RNTI IE and the Access PCIIE in the UE Context ID IE. If the Index to RAT/Frequency SelectionPriority IE is contained in the RETRIEVE UE CONTEXT RESPONSE message,the new NG-RAN node may store this information. If the LocationReporting Information IE is included in the RETRIEVE UE CONTEXT RESPONSEmessage, then the new NG-RAN node may initiate the requested locationreporting functionality.

In an example, if the old NG-RAN node is not able to identify the UEcontext by means of the UE Context ID, or if the integrity protectioncontained in the RETRIEVE UE CONTEXT REQUEST message is not valid, or,if it decides not to provide the UE context to the new NG-RAN node, itmay respond to the new NG-RAN node with the RETRIEVE UE CONTEXT FAILUREmessage. If the Old NG-RAN node to New NG-RAN node Resume Container IEis included in the RETRIEVE UE CONTEXT FAILURE message, the new NG-RANnode may transparently forward the content of this IE to the UE.

In an example embodiment, the RETRIEVE UE CONTEXT REQUEST/RESPONSEmessage may comprise one or more closed access group identifiers (CAGIDs) associated with the UE.

In an example embodiment, the RETRIEVE UE CONTEXT REQUEST/RESPONSEmessage may comprise the closed access group restriction indicator (aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like).

In an example embodiment, the RETRIEVE UE CONTEXT REQUEST/RESPONSEmessage may comprise the requested NSSAI for the CAG, [mapping of(requested) NSSAI for the CAG], default configured NSSAI indication forone or more CAGs associated with the wireless device/UE, and/or thelike.

In an example embodiment, based on one or more of the one or more closedaccess group identifiers (CAG IDs) associated with the UE, the closedaccess group restriction indicator, the requested NSSAI for the CAG,and/or the like, a RETRIEVE UE CONTEXT FAILURE message, a HANDOVERCANCEL operation, HANDOVER PREPARATION FAILURE message, and/or the likemay be sent from the target NG-RAN node to the source NG-RAN node. In anexample, the target RAN (NG-RAN) node may reject the handover if the UEcell access (CAG) restrictions do not allow the UE to handover to thetarget cell of the target NG-RAN. In an example, the target RAN (NG-RAN)node may reject the handover if one or more CAGs (CAG IDs) associatedwith the UE is not served/supported by the target cells of the targetNG-RAN node.

In an example embodiment, cell level mobility may require (explicit) RRCsignalling to be triggered, e.g., handover. For inter-gNB handover, thesignalling procedures may comprise the following. A source gNB mayinitiate a handover and may issue a handover request over the Xninterface. A target gNB may perform admission control and may providethe RRC configuration as part of the Handover Acknowledgement. Thesource gNB may provide the RRC configuration to the UE in the HandoverCommand. The Handover Command message may comprise at least cell ID andall information required to access the target cell so that the UE canaccess the target cell without reading system information. For somecases, the information required for contention-based and contention-freerandom access may be included in the handover command message. Theaccess information to the target cell may include beam specificinformation, if any. The UE may move the RRC connection to the targetgNB and replies the handover complete.

The handover mechanism triggered by RRC may require the UE at least toreset the MAC entity and re-establish RLC. RRC managed handovers withand without PDCP entity re-establishment are both supported. For DRBsusing RLC AM mode, PDCP may be re-established together with a securitykey change or initiate a data recovery procedure without a key change.For DRBs using RLC UM mode and for SRBs, PDCP may be re-establishedtogether with a security key change or remain as it is without a keychange. Timer based handover failure procedure may be supported in NR.RRC connection re-establishment procedure may be employed for recoveringfrom handover failure. Beam Level Mobility does not require explicit RRCsignalling to be triggered. The gNB may provide via RRC signalling theUE with measurement configuration comprising configurations of SSB/CSIresources and resource sets, reports and trigger states for triggeringchannel and interference measurements and reports. SSB-based Beam LevelMobility may be based on the SSB associated to the initial DL BWP andcan only be configured for the initial DL BWPs and for DL BWPscontaining the SSB associated to the initial DL BWP. For other DL BWPs,Beam Level Mobility may be performed based on CSI-RS.

In an example embodiment, an intra-NR RAN handover may perform thepreparation and execution phase of the handover procedure performedwithout involvement of the 5GC, e.g., preparation messages may bedirectly exchanged between the gNBs. The release of the resources at thesource gNB during the handover completion phase may be triggered by thetarget gNB.

In an example embodiment, the UE context within the source gNB maycomprise information regarding roaming and access restrictions whichwere provided either at connection establishment or at the last TAupdate. The source gNB may configures the UE measurement procedures andthe UE reports according to the measurement configuration. The sourcegNB may determine/decide to handover the UE, based on Measurement Reportand RRM information. The source gNB may issue a handover request messageto the target gNB by passing/transmitting a transparent RRC containerwith necessary information to prepare the handover at the target side.The information may comprise at least the target cell ID, KgNB, theC-RNTI of the UE in the source gNB, RRM-configuration including UEinactive time, basic AS-configuration including antenna Info and DLCarrier Frequency, the current QoS flow to DRB mapping rules applied tothe UE, the SIB 1 from source gNB, the UE capabilities for differentRATs, PDU session related information, and may comprise the UE reportedmeasurement information including beam-related information if available.The PDU session related information may comprise the slice information(if supported) and QoS flow level QoS profile(s). In an example,admission control may be performed by the target gNB. Slice-awareadmission control may be performed if the slice information is sent tothe target gNB.

In an example embodiment, the Slice-aware admission control may furthercomprise determining by the gNB that one or more requested slices orS-NSSAIs may not belong or be mapped to one or more CAGs. In an example,the gNB may determine not to admit based on CAG restrictions, NSSAImapping of CAGs, and/or the like. The admission control may furthercomprise determining the admissibility based on the one or more of theone or more closed access group identifiers (CAG IDs) associated withthe UE, the closed access group restriction indicator, the requestedNSSAI for the CAG, and/or the like.

In an example, if the PDU sessions are associated with non-supportedslices the target gNB may reject such PDU Sessions. The target gNB mayprepare the handover with L1/L2 and may send the HANDOVER REQUESTACKNOWLEDGE to the source gNB, which may comprise a transparentcontainer to be sent to the UE as an RRC message to perform thehandover. The source gNB may trigger the Uu handover by sending anRRCReconfiguration message to the UE, comprising the informationrequired to access the target cell e.g., at least the target cell ID,the new C-RNTI, the target gNB security algorithm identifiers for theselected security algorithms, and/or the like. It may also include a setof dedicated RACH resources, the association between RACH resources andSSB(s), the association between RACH resources and UE-specific CSI-RSconfiguration(s), common RACH resources, and system information of thetarget cell, and/or the like. The source gNB may send the SN STATUSTRANSFER message to the target gNB. The UE may synchronise to the targetcell and may complete the RRC handover procedure by sendingRRCReconfigurationComplete message to target gNB. The target gNB maysends a PATH SWITCH REQUEST message to the AMF to trigger 5GC to switchthe DL data path towards the target gNB and to establish an NG-Cinterface instance towards the target gNB. 5GC may switch the DL datapath towards the target gNB. The UPF may send one or more “end marker”packets on the old path to the source gNB per PDU session/tunnel andthen may release any U-plane/TNL resources towards the source gNB. TheAMF may confirms the PATH SWITCH REQUEST message with the PATH SWITCHREQUEST ACKNOWLEDGE message. Upon reception of the PATH SWITCH REQUESTACKNOWLEDGE message from the AMF, the target gNB may send the UE CONTEXTRELEASE to inform the source gNB about the success of the handover. Thesource gNB may release radio and C-plane related resources associated tothe UE context. Any ongoing data forwarding may continue. The RRMconfiguration may comprise beam measurement information (for layer 3mobility) associated to SSB(s), CSI-RS(s) for the reported cell(s) ifboth types of measurements are available, and/or the like.

In an example, the U-plane handling during the Intra-NR-Access mobilityactivity for UEs in RRC_CONNECTED may take the following principles intoaccount to avoid data loss during HO. During HO preparation U-planetunnels may be established between the source gNB and the target gNB.During HO execution, user data may be forwarded from the source gNB tothe target gNB. Forwarding may take place in order as long as packetsare received at the source gNB from the UPF or the source gNB buffer hasnot been emptied.

In an example, during HO completion, the target gNB may send a pathswitch request message to the AMF to inform that the UE has gainedaccess and the AMF may trigger path switch related 5GC internalsignalling and actual path switch of the source gNB to the target gNB inUPF. The source gNB may continue forwarding data as long as packets arereceived at the source gNB from the UPF or the source gNB buffer has notbeen emptied.

In an example, for RLC-AM bearers, for in-sequence delivery andduplication avoidance, PDCP SN may be maintained on a per DRB basis andthe source gNB may inform the target gNB about the next DL PDCP SN toallocate to a packet which does not have a PDCP sequence number. Forsecurity synchronization, HFN may be maintained and the source gNB mayprovide to the target one reference HFN for the UL and one for the DLe.g., HFN and corresponding SN. In both the UE and the target gNB, awindow-based mechanism may be employed for duplication detection andreordering. The occurrence of duplicates over the air interface in thetarget gNB may be minimized by means of PDCP SN based reporting at thetarget gNB by the UE. In uplink, the reporting may be configured on aper DRB basis by the gNB and the UE may first start by transmittingthose reports when granted resources are in the target gNB. In downlink,the gNB may decide when and for which bearers a report may be sent andthe UE may not wait for the report to resume uplink transmission. Thetarget gNB may re-transmit and prioritize downlink data forwarded by thesource gNB (i.e. the target gNB may first send all forwarded PDCP SDUswith PDCP SNs, then all forwarded downlink PDCP SDUs without SNs beforesending new data from 5GC). The UE may re-transmit in the target gNBuplink PDCP SDUs starting from the oldest PDCP SDU that has not beenacknowledged at RLC in the source.

In an example, for RLC-UM bearers, the PDCP SN and HFN may be reset inthe target gNB. No PDCP SDUs are retransmitted in the target gNB, thetarget gNB may prioritise downlink SDAP SDUs forwarded by the source gNBover the data from the core network. The UE may not retransmit any PDCPSDU in the target cell for which transmission had been completed in thesource cell.

The intra NR handover may further comprise data forwarding. In anexample, the source NG-RAN node may determine/suggest downlink dataforwarding per QoS flow established for a PDU session and may provideinformation how it maps QoS flows to DRBs. The target NG-RAN node maydetermine/decide data forwarding per QoS flow established for a PDUSession. If “lossless handover” is required and the QoS flows to DRBmapping applied at the target NG-RAN node allows applying for dataforwarding the same QoS flows to DRB mapping as applied at the sourceNG-RAN node for a DRB and if all QoS flows mapped to that DRB areaccepted for data forwarding, the target NG-RAN node establishes adownlink forwarding tunnel for that DRB. For a DRB for whichpreservation of SN status applies, the target NG-RAN node maydecide/determine to establish an UL data forwarding tunnel. The targetNG-RAN node may determine/decide to establish a downlink forwardingtunnel for each PDU session. In this case the target NG-RAN node mayprovide information for which QoS flows data forwarding has beenaccepted and corresponding UP TNL information for data forwardingtunnels to be established between the source NG-RAN node and the targetNG-RAN node. As long as data forwarding of DL user data packets takesplace, the source NG-RAN node may forward user data in the sameforwarding tunnel. For any QoS flow accepted for data forwarding by thetarget NG-RAN node and for which a DRB DL forwarding tunnel wasestablished for a DRB to which this QoS flow was mapped at the sourceNG-RAN node, any fresh packets of this QoS flow may be forwarded as PDCPSDUs via the mapped DRB DL forwarding tunnel. For DRBs for whichpreservation of SN status applies, the source NG-RAN node may forward inorder to the target NG-RAN node via the DRB DL forwarding tunnel alldownlink PDCP SDUs with their SN corresponding to PDCP PDUs which havenot been acknowledged by the UE. For any QoS flow accepted for dataforwarding by the target NG-RAN node for which a DL PDU sessionforwarding tunnel was established, the source NG-RAN node may forwardSDAP SDUs as received on NG-U from the UPF. As long as data forwardingof UL user data packets takes place for DRBs for which preservation ofSN status applies the source NG-RAN node may discard the uplink PDCPPDUs received out of sequence if the source NG-RAN node has not acceptedthe request from the target NG-RAN node for uplink forwarding or if thetarget NG-RAN node has not requested uplink forwarding for the bearerduring the Handover Preparation procedure. The source NG-RAN node mayforward to the target NG-RAN node the uplink PDCP SDUs with their SNcorresponding to PDCP PDUs received out of sequence if the source NG-RANnode has accepted the request from the target NG-RAN node for uplinkforwarding for the bearer during the Handover Preparation procedure.

In an example, handling of end marker packets may comprise thefollowing. The source NG-RAN node may receive one or several GTP-U endmarker packets per PDU session from the UPF and may replicate the endmarker packets into one or more data forwarding tunnel when no more userdata packets are to be forwarded over that tunnel. End marker packetssent via a data forwarding tunnel may be applicable to all QoS flowsforwarded via that tunnel. After end marker packets have been receivedover a forwarding tunnel, the target NG-RAN node may start taking intoaccount the packets of QoS flows associated with that forwarding tunnelreceived at the target NG-RAN node from the NG-U PDU session tunnel.

In an example, a UE in RRC_CONNECTED may initiate the re-establishmentprocedure to continue the RRC connection when a failure condition occurs(e.g., radio link failure, reconfiguration failure, integrity checkfailure, and/or the like). The UE may re-establish the connection,providing the UE Identity (PCI+C-RNTI) to the gNB where the trigger forthe re-establishment occurred. If the UE Context is not locallyavailable, the gNB, may request the last serving gNB to provide UEContext data. The last serving gNB may provide the UE context data. ThegNB may continue the re-establishment of the RRC connection. The messagemay be sent on SRB1. The gNB may perform the reconfiguration tore-establish SRB2 and DRBs when the re-establishment procedure isongoing. If loss of DL user data buffered in the last serving gNB may beprevented, the gNB may provide forwarding addresses. The gNB may performpath switch. The gNB may trigger the release of the UE resources at thelast serving gNB.

In an example embodiment, in RRC_CONNECTED mode, the network may controlUE mobility, for example, the network may decide when the UE connects towhich NR cell(s) or inter-RAT cell (e.g., E-UTRA). For networkcontrolled mobility in RRC_CONNECTED, the PCell may be changed using anRRC Connection Reconfiguration message including the mobilityControlInfo(handover). The SCell(s) may be changed using the RRC ConnectionReconfiguration message either with or without the mobilityControlInfo.The network may trigger the handover procedure e.g. based on radioconditions, load, QoS, UE category, and/or the like. To facilitate this,the network may configure the UE to perform measurement reporting(possibly including the configuration of measurement gaps). The networkmay also initiate handover blindly, for example without having receivedmeasurement reports from the UE. Before sending the handover message tothe UE, the source gNB may prepare one or more target cells. The sourcegNB may select the target PCell. The source gNB may also provide thetarget gNB with a list of best cells on each frequency for whichmeasurement information is available, for example, in order ofdecreasing RSRP. The source gNB may also include available measurementinformation for the cells provided in the list. The target gNB maydecide which SCells are configured for use after handover, which mayinclude cells other than the ones indicated by the source gNB.

According to some of the various aspects of embodiments, the target gNBmay generate a message used to configure the UE for the handover, forexample, the message including the access stratum configuration to beused in the target cell(s). The source gNB may transparently (forexample, does not alter values/content) forward the handovermessage/information received from the target gNB to the UE. Whenappropriate, the source gNB may initiate data forwarding for (a subsetof) the dedicated radio bearers. After receiving the handover message,the UE may attempt to access the target PCell at the available RACHoccasion according to a random access resource selection. Whenallocating a dedicated preamble for the random access in the targetPCell, RAN may ensure the preamble is available from the first RACHoccasion the UE may use. Upon successful completion of the handover, theUE may send a message used to confirm the handover to the target gNB.

According to some of the various aspects of embodiments, if the targetgNB does not support the release of RRC protocol which the source gNBused to configure the UE, the target gNB may be unable to comprehend theUE configuration provided by the source gNB. In this case, the targetgNB may use the full configuration option to reconfigure the UE forhandover and re-establishment. Full configuration option includes aninitialization of the radio configuration, which makes the procedureindependent of the configuration used in the source cell(s) with theexception that the security algorithms are continued for the RRCre-establishment.

According to some of the various aspects of embodiments, after thesuccessful completion of handover, PDCP SDUs may be re-transmitted inthe target cell(s). This may apply for dedicated radio bearers usingRLC-AM mode and/or for handovers not involving full configurationoption. After the successful completion of handover not involving fullconfiguration option, the SN (sequence number) and/or the HFN (hyperframe number) may be reset for some radio bearers. For the dedicatedradio bearers using RLC-AM mode both SN and HFN may continue. Forreconfigurations involving the full configuration option, the PDCPentities may be newly established (SN and HFN may not continue) fordedicated radio bearers irrespective of the RLC mode. UE behaviour to beperformed upon handover may be the same regardless of the handoverprocedures used within the network (e.g. whether the handover includesXn or N2 signaling procedures).

The source gNB may, for some time, maintain a context to enable the UEto return in case of handover failure. After having detected handoverfailure, the UE may attempt to resume the RRC connection either in thesource PCell or in another cell using the RRC re-establishmentprocedure. This connection resumption may succeed if the accessed cellis prepared. For example, when the access cell is a cell of the sourcegNB or of another gNB towards which handover preparation has beenperformed. The cell in which the re-establishment procedure succeedsbecomes the PCell while SCells, if configured, may be released.

Normal measurement and mobility procedures may be used to supporthandover to cells broadcasting a CSG (closed subscriber group) identity.In addition, RAN may configure the UE to report that it is entering orleaving the proximity of cell(s) included in its CSG whitelist. RAN mayrequest the UE to provide additional information broadcast by thehandover candidate cell e.g. cell global identity, CSG identity, CSGmembership status. RAN may use the proximity report to configuremeasurements as well as to decide whether or not to request additionalinformation broadcast by the handover candidate cell. The additionalinformation may be used to verify whether or not the UE is authorized toaccess the target PCell and may also be needed to identify handovercandidate cell. This may involve resolving PCI confusion, for example,when the physical layer identity that is included in the measurementreport may not uniquely identify the cell.

The purpose of RRC connection reconfiguration procedure may be to modifyan RRC connection, e.g. to establish, modify and/or release RBs, toperform handover, to setup, modify, and/or release measurements, to add,modify, and/or release SCells. As part of the procedure, NAS dedicatedinformation may be transferred from RAN to the UE. If the received RRC(Connection) Reconfiguration message includes the sCellToReleaseList, UEperforms SCell release. If the received RRC Connection Reconfigurationmessage includes the sCellToAddModList, UE performs SCell additions ormodification.

The UE context within the source gNB may contain information regardingroaming/handover restrictions which may be provided either at connectionestablishment or at the last TA (tracking area) update process. Thesource gNB may configure the UE measurement procedures employing atleast one RRC connection reconfiguration message. The UE may betriggered to send at least one measurement report by the rules set by,for example, system information, RRC configuration, and/or the like. Thesource gNB may make a handover decision based on many parameters, forexample, the measurement reports, RRM information, traffic and load, acombination of the above, and/or the like. The source gNB may initiatethe handover procedure by sending a handover request message to one ormore potential target gNBs. When the source gNB sends the handoverrequest message, it may start a handover preparation timer. Uponreception of the handover request acknowledgement message the source gNBmay stop the handover preparation timer.

In an Xn handover process, the source gNB may transmit a handoverrequest message to one or more potential target gNB passing informationto prepare the handover at the target side. The handover request messagemay comprise one or more closed access group identifiers associated withthe UE. The handover request message may comprise the closed accessgroup restriction indicator (a CAG-only indication, a CAG-only UEindication, a cell mobility restriction for the UE, and/or the like. Inan example embodiment, handover request message may further comprise therequested NSSAI for the CAG, [mapping of (requested) NSSAI for the CAG],default configured NSSAI indication for one or more CAGs associated withthe wireless device/UE, and/or the like. In an example, a MobilityRestriction IE in the handover request message may comprise the one ormore closed access group identifiers associated with the UE, the closedaccess group restriction indicator (a CAG-only indication, a CAG-only UEindication, a cell mobility restriction for the UE, and/or the like),the requested NSSAI for the CAG, [mapping of (requested) NSSAI for theCAG], default configured NSSAI indication for one or more CAGsassociated with the wireless device/UE, and/or the like. In an exampleembodiment, a UE context information IE in the handover request messagemay comprise the one or more closed access group identifiers associatedwith the UE, the closed access group restriction indicator (a CAG-onlyindication, a CAG-only UE indication, a cell mobility restriction forthe UE, and/or the like), the requested NSSAI for the CAG, [mapping of(requested) NSSAI for the CAG], default configured NSSAI indication forone or more CAGs associated with the wireless device/UE, and/or thelike.

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise one or more closed access group identifiersassociated with the UE.

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like).

In an example embodiment, the handover required message, the handovercommand message, mobility restriction IE, the handover request message,and/or the like may comprise the requested NSSAI for the CAG, [mappingof (requested) NSSAI for the CAG], default configured NSSAI indicationfor one or more CAGs associated with the wireless device/UE, and/or thelike.

In an N2 handover process without AMF relocation, the source gNB maytransmit a handover required message to an AMF for one or more potentialtarget gNB, and the AMF may transmit a handover request message to thepotential target gNBs. The handover required message and/or the handoverrequest message may pass information to prepare the handover at thetarget side. The handover required message and/or the handover requestmessage may comprise the one or more closed access group identifiersassociated with the UE, the closed access group restriction indicator (aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like), the requested NSSAI for theCAG, [mapping of (requested) NSSAI for the CAG], default configuredNSSAI indication for one or more CAGs associated with the wirelessdevice/UE, and/or the like. In an example, a Source to TargetTransparent Container IE in the handover required message and/or thehandover request message may contain the one or more closed access groupidentifiers associated with the UE, the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like), the requested NSSAIfor the CAG, [mapping of (requested) NSSAI for the CAG], defaultconfigured NSSAI indication for one or more CAGs associated with thewireless device/UE, and/or the like.

In an N2 handover process relocating an AMF, the source gNB may transmita handover required message to a source AMF for one or more potentialtarget gNB, the source AMF may transmit a forward relocation requestmessage to one or more potential target AMFs serving the potentialtarget gNBs, and the potential target AMFs may transmit a handoverrequest message to the potential target gNBs. The handover requiredmessage, the forward relocation request message, and/or the handoverrequest message may pass information to prepare the handover at thetarget side. The handover required message, the forward relocationrequest message, and/or the handover request message may comprise theone or more closed access group identifiers associated with the UE, theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], allowed NSSAIs per CAG, default configured NSSAIindication for one or more CAGs associated with the wireless device/UE,and/or the like. In an example, a Source to Target Transparent ContainerIE in the handover required message and/or the handover request messagemay contain the one or more closed access group identifiers associatedwith the UE, the closed access group restriction indicator (a CAG-onlyindication, a CAG-only UE indication, a cell mobility restriction forthe UE, and/or the like), the requested NSSAI for the CAG, [mapping of(requested) NSSAI for the CAG], allowed NSSAIs per CAG, defaultconfigured NSSAI indication for one or more CAGs associated with thewireless device/UE, and/or the like. In an example, an RAN TransparentContainer IE in the forward relocation request message may contain theone or more closed access group identifiers associated with the UE, theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], allowed NSSAIs per CAG, default configured NSSAIindication for one or more CAGs associated with the wireless device/UE,and/or the like.

During the handover preparation phase, the serving gNB may transmit theone or more closed access group identifiers associated with the UE, theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like), the requested NSSAI for the CAG, [mapping of (requested)NSSAI for the CAG], allowed NSSAIs per CAG, default configured NSSAIindication for one or more CAGs associated with the wireless device/UE,and/or the like to one or more potential target gNBs. This informationmay be employed, at least in part, by the potential target gNB, forexample, to configure the UE admission control, accept/reject a handoverrequest, and/or the like. This information may be employed, at least inpart, by the potential target gNB, for example, to transmit to the nextone or more potential gNBs that the UE may handover. This informationmay be employed, at least in part, by the potential target gNB, forexample, to determine the one or more cells (the CAG cells, normalcells, and/or the like that may serve the UE and that may be employedafter completing the handover.

The target gNB may employ the one or more closed access groupidentifiers associated with the UE, the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like, the requested NSSAIfor the CAG, [mapping of (requested) NSSAI for the CAG], allowed NSSAIsper CAG, default configured NSSAI indication for one or more CAGsassociated with the wireless device/UE, and/or the like in order toproperly configure the UE before UE connects to the target gNB. Thetarget gNB may configure the UE considering the one or more closedaccess group identifiers associated with the UE, the closed access grouprestriction indicator (a CAG-only indication, a CAG-only UE indication,a cell mobility restriction for the UE, and/or the like, the requestedNSSAI for the CAG, [mapping of (requested) NSSAI for the CAG], allowedNSSAIs per CAG, default configured NSSAI indication for one or more CAGsassociated with the wireless device/UE, and/or the like. For example, ifthe UE does not support the CAG IDs associated with one or more cells ofthe target gNB, the target gNB may reject the request by sending ahandover failure message with an appropriate error cause, and/or thelike.

Handover admission control may be performed by the target gNB dependenton many factors, for example, QoS required for the UE bearers, UEcapabilities, UE configuration, target gNB load, a combination of theabove, and/or the like. The target gNB may configure the requiredresources according to the received information from the serving gNB andmay reserve a C-RNTI and/or a RACH preamble. The access stratumconfiguration to be used in the target cell may be specifiedindependently (for example as an establishment) or as a delta comparedto the access stratum-configuration used in the source cell (for exampleas a reconfiguration).

The target gNB may prepare handover with L1/L2 and may send the handoverrequest acknowledge message to the source gNB. In an Xn handoverprocedure, the handover request acknowledge message may include atransparent container to be sent to the UE as an RRC message to performthe handover. In an N2 handover procedure without AMF relocation, thehandover request acknowledge message from the target gNB to the AMFand/or the handover command message from the AMF to the source gNB mayinclude a transparent container to be sent to the UE as an RRC messageto perform the handover. In an N2 handover procedure relocating an AMF,the handover request acknowledge message from the target gNB to thetarget AMF, the forward relocation response message from the target AMFto the source AMF, and/or the handover command message from the sourceAMF to the source gNB may include a transparent container to be sent tothe UE as an RRC message to perform the handover. The container mayinclude a new C-RNTI, target gNB security algorithm identifiers for theselected security algorithms, a dedicated RACH preamble, accessparameters, SIB s, and/or other configuration parameters. Thetransparent container may further comprise the one or more closed accessgroup identifiers associated with the UE, the closed access grouprestriction indicator (a CAG-only indication, a CAG-only UE indication,a cell mobility restriction for the UE, and/or the like), the requestedNSSAI for the CAG, [mapping of (requested) NSSAI for the CAG], allowedNSSAIs per CAG, default configured NSSAI indication for one or more CAGsassociated with the wireless device/UE, and/or the like. The target gNBmay modify the transparent container, context of the UE, and/or the likeor may keep the same transparent container, context, and/or the likethat the UE has with the serving base station. The target gNB maygenerate the RRC message to perform the handover, for example, RRCconnection reconfiguration message including the mobility controlinformation. The RRC message may be sent by the source gNB towards theUE.

The source gNB may perform the necessary integrity protection andciphering of the message. The UE may receive the RRC connectionreconfiguration message from the source gNB and may start performing thehandover. The UE may not need to delay the handover execution fordelivering the HARQ/ARQ responses to the source gNB.

After receiving the RRC connection reconfiguration message including themobility control information, UE may perform synchronization to thetarget gNB and accesses the target cell via RACH on the primary cell.The UE Random access procedure may employ a contention-free procedure ifa dedicated RACH preamble was indicated in the mobility controlinformation. The UE random access procedure may employ acontention-based procedure if no dedicated preamble was indicated. TheUE may derive target gNB specific keys and may configure the selectedsecurity algorithms to be used in the target cell. The target gNB mayrespond with uplink allocation and timing advance.

After the UE has successfully accessed the target cell, the UE may sendan RRC connection reconfiguration complete message (C-RNTI) to confirmthe handover and to indicate that the handover procedure is completedfor the UE. UE may transmit a MAC uplink Buffer Status Report (BSR)Control Element (CE) along with the uplink RRC ConnectionReconfiguration Complete message or may transmit a MAC uplink BSR CEwhenever possible to the target gNB. In an example, UE may transmit,along with the RRC Connection Reconfiguration Complete message, a pathswitch request message that the receiving gNB may consider whenswitching the DL data path towards the target gNB and to establish anNG-C interface instance towards the target gNB for the UE. The targetgNB verifies the C-RNTI sent in the RRC (Connection) ReconfigurationComplete message. The target gNB may now begin sending data to the UEand receiving data from the UE.

After receiving the RRC (Connection) Reconfiguration Complete message,the target gNB may release the UE resources at the last serving gNB.

In an example embodiment as depicted in FIG. 21, an inter NG-RAN node N2based handover procedure without Xn interface may be employed. In anexample, the source NG-RAN may determine/decide to initiate an N2-basedhandover to the target NG-RAN. This may be triggered, for example, dueto new radio conditions or load balancing, if there is no Xnconnectivity to the target NG-RAN, an error indication from the targetNG-RAN after an unsuccessful Xn-based handover (i.e. no IP connectivitybetween T-RAN and S-UPF), based on dynamic information learnt by theS-RAN, and/or the like. The availability of a direct forwarding path maybe determined in the source NG-RAN and indicated to the SMFs. If IPconnectivity is available between the source and target NG-RAN andsecurity association(s) is in place between them, a direct forwardingpath is available. If a direct forwarding path is not available,indirect forwarding may be used. The SMFs may employ the indication fromthe source NG-RAN to determine whether to apply indirect forwarding. Inthe case of handover to a shared network, the source NG-RAN maydetermine a PLMN to be used in the target network. The source NG-RAN mayindicate the selected PLMN ID, NPN ID, CAG ID, and/or the like to beused in the target network to the AMF as part of the Tracking Area sentin the HO Required message. If the AMF may generate the N2 downlinksignalling during the ongoing handover and may receive a rejection to aN2 interface procedure (e.g. DL NAS message transfer; Location reportingcontrol, and/or the like) from the NG-RAN with an indication that anInter NG-RAN node handover procedure is in progress, the AMF mayreattempt the same N2 interface procedure either when the handover iscomplete or the handover is deemed to have failed if the AMF is stillthe serving AMF, when possible. If the Inter NG-RAN node handoverchanges the serving AMF, the source AMF may terminate any other ongoingN2 interface procedures except the handover procedure. In an example, ifduring the handover procedure the AMF determines/detects that the AMFneeds be changed, the AMF may reject any SMF initiated N2 requestreceived since handover procedure started and may include an indicationthat the request has been temporarily rejected due to handover procedurein progress. Upon reception for an SMF initiated N1 and/or N2 request(s)with an indication either from the NG-RAN (via N2 SM Info) or AMF thatthe request has been temporarily rejected due to handover procedure inprogress, the SMF may stars a locally configured guard timer. The SMFmay hold any signalling messages targeted towards AMF for a given UEduring the handover preparation phase unless it detects that thehandover execution is completed or handover has failed/cancelled. TheSMF may re-attempt, up to a pre-configured number of times, when eitherit detects that the handover is completed or has failed using messagereception or at expiry of the guard timer.

In an example as depicted in FIG. 21, a S-RAN may send to a S-AMF aHandover Required message. The handover required message may comprise aTarget ID, Source to Target transparent container, SM N2 info list, PDUSession IDs, intra system handover indication. In an example, the TargetID may comprise a selected PLMN ID, NPN ID, NID, CAG ID, and/or thelike. The Source to Target transparent container may comprise NG-RANinformation created by S-RAN to be used by T-RAN, and may be transparentto 5GC. It may further comprise for each PDU session the correspondingUser Plane Security Enforcement information, QoS flows/DRBs informationsubject to data forwarding. All PDU Sessions handled by S-RAN (e.g., allexisting PDU Sessions with active UP connections) may be included in theHandover Required message, indicating which of those PDU Session(s) arerequested by S-RAN to handover. The SM N2 info may comprise DirectForwarding Path Availability (indication) if direct data forwarding isnot available. Direct Forwarding Path Availability may indicate whetherdirect forwarding is available from the S-RAN to the T-RAN. Thisindication from S-RAN may be based on e.g., the presence of IPconnectivity and security association(s) between the S-RAN and theT-RAN.

In an example, T-AMF Selection may be performed. When the S-AMF can'tserve the UE anymore, the S-AMF may select the T-AMF. In an example, theT-AMF may be selected based on CAGs, CAG IDs, NPN support, and/or thelike.

In an example embodiment, the AMF selection functionality may beapplicable to both 3GPP access and non-3GPP access. The AMF selectionfunctionality may be supported by the 5G-AN (e.g. RAN, N3IWF) and may beemployed to select an AMF for a given UE. An AMF may support the AMFselection functionality to select an AMF for relocation or because theinitially selected AMF may not be an appropriate AMF to serve the UE(e.g. due to CAG restriction, NPN, allowed NSSAI for the CAGs associatedwith the UE, due to change of Allowed NSSAI, and/or the like). Other CPNF(s), e.g. SMF, may support the AMF selection functionality to selectan AMF from the AMF set when the original AMF serving a UE isunavailable.

5G-AN, RAN, NG-RAN, and/or the like may select an AMF Set and an AMFfrom the AMF Set. The AMF selection functionality in the 5G-AN mayconsider the following factors for selecting the AMF Set: AMF Region IDand AMF Set ID derived from GUAMI, Requested NSSAI, Local operatorpolicies, one or more CAG IDs, CAGs, NPN ID, CAG restrictionindicator(s), and/or the like. AMF selection functionality in the 5G-ANor CP NFs may consider the following factors for selecting an AMF fromAMF Set: Availability of candidate AMFs, Load balancing across candidateAMFs (e.g. considering weight factors of candidate AMFs in the AMF Set),and/or the like.

In an example, the AMF or other CP NFs may employ an NRF to discover theAMF instance(s) unless AMF information is available by other means, e.g.locally configured on AMF or other CP NFs. A Nnrf discovery andselection procedure may be employed. The AMF may send a Nnrf discoveryrequest to the NRF indicating the CAGs, CAG ID, CAG restrictionindicators, and/or the like. The NRF may provide the IP address or theFQDN of AMF instance(s) or the Endpoint Address(es) of AMF serviceinstance(s) to the AMF or other CP NFs. The AMF selection function inthe AMF or other CP NFs may select an AMF instance based on theavailable AMF instances (obtained from the NRF or locally configured inthe AMF or other CP NFs). In an example, the AMF selection functionalityin AMF or other CP NFs may employ GUAMI, TAI to discover the AMFinstance(s), the NRF may provides the IP address, or the FQDN of theassociated AMF instance(s) or the Endpoint Address(es) of the associatedAMF service instance(s) if it is available. If the associated AMF isunavailable due to AMF planned removal, the backup AMF used for plannedremoval may be provided by the NRF. If the associated AMF is unavailabledue to AMF failure, the backup AMF used for failure may be provided bythe NRF. If no AMF instances related to the indicated GUAMI can be foundor AMF Pointer value used by more than one AMF is found, a list ofcandidate AMF instances in the same AMF Set together with additionalinformation (e.g. priority) may be provided by the NRF. The NRF mayprovide the TAI(s), if available. In this case, other CP NF may selectany AMF instance from the list of candidate AMF instances. AMF selectionfunctionality in AMF may employ AMF Set ID to discover the AMFinstance(s), the NRF may provide a list of AMF/AMF service instances inthe same AMF Set together with additional information (e.g.

PRIORITY

At intra-PLMN mobility, the AMF selection functionality in source AMFmay employ CAG IDs supported by the source AMF, source AMF Set ID,source AMF Region ID, and the target location information, S-NSSAI(s) ofAllowed NSSAI to discover target AMF instance(s), and/or the like. TheNRF may provide the target AMF instance belonged to the target AMF setin target AMF Region which may be the mapping of the source AMF set insource AMF region. In an example, at inter PLMN mobility, inter NPNmobility, mobility within one or more CAGs, the source AMF may select anAMF in the target PLMN, NPN, CAG, via the PLMN, NPN, CAG level NRF.

In an example, the S-AMF may send to the T-AMF, aNamf_Communication_CreateUEContext Request. The request may comprise N2Information (e.g., Target ID, Source to Target transparent container, SMN2 information list, PDU Session IDs, Service area restriction, and/orthe like), UE context information (e.g., SUPI, Allowed NSSAI for eachAccess Type if available, Tracing Requirements, the list of PDU SessionIDs along with the corresponding SMF information and the correspondingS-NSSAI(s), PCF ID(s), DNN, and/or the like), and/or the like. If thesubscription information includes Tracing Requirements, the old AMF mayprovide the target AMF with Tracing Requirements. In an example, theNamf_Communication_CreateUEContext Request message may further comprisethe one or more closed access group identifiers associated with the UE,the closed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like, the requested NSSAI for the CAG, allowed NSSAI per CAG,[mapping of (requested) NSSAI for the CAG], default configured NSSAIindication for one or more CAGs associated with the wireless device/UE,and/or the like.

In an example, the S-AMF may initiate a handover resource allocationprocedure by invoking the Namf_Communication_CreateUEContext serviceoperation towards the T-AMF. If Service area restrictions are availablein the S-AMF, they may be forwarded to the T-AMF. If both Home andVisited PCF ID(s) are provided by the S-AMF, the T-AMF may contact the(V-) PCF identified by the (V-)PCF ID. If the (V-)PCF identified by the(V-)PCF ID is not used or there are no PCF ID(s) received from theS-AMF, the T-AMF may select the PCF(s). The T-AMF may inform the S-AMFthat the PCF ID is not used and then the S-AMF may terminate the AMPolicy Association with the PCF identified by the PCF ID. In an example,the T-AMF may send to the SMF, a Nsmf_PDUSession_UpdateSMContext thatmay comprise PDU Session ID, Target ID, T-AMF ID, N2 SM Info (SecondaryRAT Usage Data), and/or the like. For one or more PDU Session(s)indicated by S-RAN, the AMF may invoke theNsmf_PDUSession_UpdateSMContext Request to the associated SMF. However,if the S-NSSAI associated with PDU Session is not available in theT-AMF, the T-AMF may not invoke Nsmf_PDUSession_UpdateSMContext for thisPDU Session. The PDU Session ID may indicate a PDU Session candidate forN2 Handover. Target ID may indicate the UE location information, CAGcells the UE is connected to, and/or the like. SM N2 Info may includethe Direct Forwarding Path Availability. If the (T-)AMFdetermines/detects that the UE moves into a non-allowed area based onService area restrictions, CAG restrictions, mobility restriction,and/or the like, the (T-)AMF may notify each SMF corresponding to thelist of PDU Sessions received from the Handover Required message thatthe UE is only reachable for regulatory prioritized services. Based onthe Target ID, the SMF may check if N2 Handover for the indicated PDUSession may be accepted. The SMF may check the UPF Selection Criteria.If the UE has moved out of the service area of the UPF connecting toNG-RAN, the SMF may select a new intermediate UPF.

The SMF may send to UPF (PSA) an N4 Session Modification Request. If theSMF selects a new UPF to act as intermediate UPF for the PDU Session,and the different CN Tunnel Info need be used, the SMF may send N4Session Modification Request message to UPF (PSA). The SMF may providethe CN Tunnel Info (on N9) if the CN Tunnel Info is allocated by theSMF, and UL Packet detection rules associate the CN Tunnel Info (on N9)to be installed on the UPF (PSA). The UPF (PSA) may send to the SMF anN4 Session Modification Response. The UPF (PSA) may send an N4 SessionEstablishment Response message to the SMF. If the UPF (PSA) allocates CNTunnel Info (on N9) of UPF (PSA), it may provide CN Tunnel Info (on N9)to the SMF. The UPF (PSA) may associate the CN Tunnel Info (on N9) withUL Packet detection rules provided by the SMF. The SMF may send to T-UPF(intermediate) an N4 Session Establishment Request. If the SMF selects anew intermediate UPF, e.g., the target UPF (T-UPF), for the PDU Sessionand if CN Tunnel Info is allocated by the T-UPF, an N4 SessionEstablishment Request message may be sent to the T-UPF, providing Packetdetection, enforcement and reporting rules to be installed on the T-UPF.The CN Tunnel Info (on N9) of UPF (PSA) for this PDU Session, which isused to setup N9 tunnel, may be provided to the T-UPF. The T-UPF(intermediate) may send to the SMF an N4 Session Establishment Response.The T-UPF may send an N4 Session Establishment Response message to theSMF with DL CN Tunnel Info and UL CN Tunnel Info (i.e. N3 tunnel info).The SMF may start a timer to release the resource of S-UPF.

In an example, the SMF may send to the T-AMF aNsmf_PDUSession_UpdateSMContext Response that may comprise PDU SessionID, N2 SM Information, Reason for non-acceptance, and/or the like. If N2handover for the PDU Session is accepted, the SMF may include in theNsmf_PDUSession_UpdateSMContext response the N2 SM Informationcontaining the N3 UP address and the UL CN Tunnel ID of the UPF and theQoS parameters indicating that the N2 SM Information is for the TargetNG-RAN. If the Direct Forwarding Path Availability indicates directforwarding is not available and the SMF knows that there is no indirectdata forwarding connectivity between source and target, the N2 SMInformation may comprise a Data forwarding not possible indication. IfN2 handover for the PDU Session is not accepted, the SMF may not includean N2 SM Information regarding the PDU Session to avoid establishment ofradio resources at the target NG-RAN. The SMF may provide a reason fornon-acceptance. If the SMF is notified that the UE is only reachable forregulatory prioritized services, the SMF may not include any N2 SM inforegarding the PDU Session for non-regulatory prioritized services toavoid establishment of radio resources at the target NG-RAN.

In an example, the T-AMF may send to the T-RAN a Handover Request(Source to Target transparent container, N2 MM Information, N2 SMInformation list, Tracing Requirements). If the subscription informationincludes Tracing Requirements, the target AMF provides the target RANwith Tracing Requirements in the Handover Request. In an example, thehandover request, one or more IEs of the handover request, and/or thelike may comprise the one or more closed access group identifiersassociated with the UE, the closed access group restriction indicator (aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like, the requested NSSAI for theCAG, allowed NSSAI per CAG, [mapping of (requested) NSSAI for the CAG],default configured NSSAI indication for one or more CAGs associated withthe wireless device/UE, and/or the like.

In an example, the source to target transparent container, and/or thelike may comprise the one or more closed access group identifiersassociated with the UE, the closed access group restriction indicator (aCAG-only indication, a CAG-only UE indication, a cell mobilityrestriction for the UE, and/or the like, the requested NSSAI for theCAG, allowed NSSAI per CAG, [mapping of (requested) NSSAI for the CAG],default configured NSSAI indication for one or more CAGs associated withthe wireless device/UE, and/or the like.

In an example, the T-AMF may determine T-RAN based on the Target ID, theone or more closed access group identifiers associated with the UE, theclosed access group restriction indicator (a CAG-only indication, aCAG-only UE indication, a cell mobility restriction for the UE, and/orthe like, the requested NSSAI for the CAG, allowed NSSAI per CAG,[mapping of (requested) NSSAI for the CAG], default configured NSSAIindication for one or more CAGs associated with the wireless device/UE,and/or the like. The T-AMF may allocate a 5G-GUTI valid for the UE inthe AMF and target TAI. The Source to Target transparent container maybe forwarded as received from S-RAN. N2 MM Information may comprisee.g., security information and Mobility Restriction List if available inthe T-AMF. The N2 SM Information list may comprise N2 SM Informationreceived from SMFs for the T-RAN in the Nsmf_PDUSession_UpdateSMContextResponse messages received within allowed max delay supervised by theT-AMF. The Mobility Restriction List may be sent in N2 MM Information ifavailable in the Target AMF. In an example, the mobility restrictionlist may further comprise the one or more closed access groupidentifiers associated with the UE, the closed access group restrictionindicator (a CAG-only indication, a CAG-only UE indication, a cellmobility restriction for the UE, and/or the like, the requested NSSAIfor the CAG, allowed NSSAI per CAG, [mapping of (requested) NSSAI forthe CAG], default configured NSSAI indication for one or more CAGsassociated with the wireless device/UE, and/or the like.

In an example, the T-RAN may send to the T-AMF a Handover RequestAcknowledge (e.g., Target to Source transparent container, List Of PDUSessions to Hand-over with for each PDU Session N2 SM information, ListOf PDU Sessions failed to be setup with for each PDU Session N2 SMinformation containing the reason for failure). The Target to Sourcetransparent container may comprise a UE container with an access stratumpart and a NAS part. The UE container may be sent transparently viaT-AMF, S-AMF and S-RAN to the UE. The T-RAN may create a List Of PDUSessions failed to be setup and reason for failure (e.g., CAGrestrictions, SMF decision, SMF response too late, or T-RAN decision,S-NSSAI is not available, unable to fulfill User Plane SecurityEnforcement, and/or the like) based on T-RAN determination. Theinformation may be provided to the S-RAN. The N2 SM information in theList Of PDU Sessions to Hand-over, may comprise per each PDU Session IDT-RAN N3 addressing information e.g., N3 UP address and Tunnel ID ofT-RAN for the PDU Session. The N2 SM information may further comprise:an Indication whether UP integrity protection is performed or not on thePDU Session, whether the PDU Session has at least one QoS Flow subjectfor data forwarding, N3 UP address and Tunnel ID of T-RAN for receivingforwarded data, and/or the like. The T-RAN may provide data forwardingaddresses for each data forwarding tunnel which it decided/determined tosetup.

In an example, the AMF may send to the SMF anNsmf_PDUSession_UpdateSMContext Request (PDU Session ID, N2 SM responsereceived from T-RAN, and/or the like). For each N2 SM response receivedfrom the T-RAN (N2 SM information included in Handover RequestAcknowledge), the AMF may send the received N2 SM response to the SMFindicated by the respective PDU Session ID. If no new T-UPF is selected,SMF may store the N3 tunnel info of T-RAN from the N2 SM response if N2handover is accepted by T-RAN. The SMF/UPF may allocate the N3 UPaddress and Tunnel IDs for indirect data forwarding corresponding to thedata forwarding tunnel endpoints established by T-RAN. The SMF may sendto the T-UPF an N4 Session Modification Request (e.g., T-RAN SM N3forwarding Information list, indication to allocate DL forwardingtunnel(s) for indirect forwarding, and/or the like). If the SMF selecteda T-UPF, the SMF may update the T-UPF by providing the T-RAN SM N3forwarding information list by sending a N4 Session Modification Requestto the T-UPF. If indirect forwarding applies based on indication fromthe S-RAN and the UPF is re-allocated and if the SMF determines/decidesto setup the indirect forwarding tunnel on the same T-UPF, the SMF mayrequest in the N4 Session Modification Request message to the T-UPF, toallocate DL forwarding tunnel(s) for indirect forwarding. Indirectforwarding may be performed via a UPF which is different from the T-UPF,in which case the SMF may select a T-UPF for indirect forwarding.

In an example, the T-UPF may send to the SMF an N4 Session ModificationResponse (T-UPF SM N3 forwarding Information list). The T-UPF mayallocate Tunnel Info and may return an N4 Session Modification Responsemessage to the SMF. The T-UPF SM N3 forwarding info list may comprise aT-UPF N3 address, a T-UPF N3 Tunnel identifiers for forwarding data.

In an example, the SMF may send to the S-UPF an N4 Session ModificationRequest (T-RAN SM N3 forwarding Information list or T-UPF SM N3forwarding Information list, indication to allocate DL forwardingtunnel(s) for indirect forwarding). If the UPF is re-allocated, thismessage may comprise the T-UPF SM N3 forwarding info list. If the UPF isnot re-allocated, this message may comprise the T-RAN SM N3 forwardinginfo list. If indirect forwarding applies based on indication fromNG-RAN and UPF allocates tunnel identities, the SMF may indicate in theN4 Session Modification Request message to the S-UPF to allocate DLforwarding tunnel(s) for indirect forwarding. Indirect forwarding may beperformed via a UPF which is different from the S-UPF.

In an example, the S-UPF may send to the SMF an N4 Session ModificationResponse (S-UPF SM N3 forwarding Information list). The S-UPF mayallocate Tunnel Info and may return an N4 Session establishment Responsemessage to the SMF. The S-UPF SM N3 forwarding Information list maycomprise S-UPF N3 address, S-UPF N3 Tunnel identifiers for DL dataforwarding, and/or the like.

The SMF may send to the T-AMF Nsmf_PDUSession_UpdateSMContext Response(N2 SM Information). The SMF may send an Nsmf_PDUSession_UpdateSMContextResponse message per PDU Session to T-AMF. The SMF may create an N2 SMinformation comprising the DL forwarding Tunnel Info to be sent to theS-RAN by the AMF. The SMF may include this information in theNsmf_PDUSession_UpdateSMContext response.

In an example, the T-AMF may send to the S-AMF,Namf_Communication_CreateUEContext Response (e.g., N2 informationnecessary for S-AMF to send Handover Command to S-RAN including Targetto Source transparent container, PDU Sessions failed to be setup list,N2 SM information (N3 DL forwarding Information, PCF ID), and/or thelike). The AMF may supervise the Nsmf_PDUSession_UpdateSMContextResponse message from the involved SMFs. At expiry of the maximum waittime or when all Nsmf_PDUSession_UpdateSMContext Response messages arereceived, the T-AMF may send the Namf_Communication_CreateUEContextResponse to the S-AMF. The PDU Sessions failed to be setup list maycomprise the List Of PDU Sessions failed to be setup received fromtarget RAN and the Non-accepted PDU session List generated by the T-AMF.Non-accepted PDU Session List may comprise following PDU Session(s) withproper cause value: Non-accepted PDU Session(s) by the SMF(s),Non-accepted PDU Session(s) by the AMF due to no response from the SMFwithin maximum wait time, Non-accepted PDU Session(s) by the AMF due tonon-available S-NSSAI in the T-AMF, and/or the like. The Target toSource transport container may be received from the T-RAN. The N2 SMInformation may be received from the SMF.

As depicted in an example FIG. 22, one or more NG-RAN, RAN, and/or thelike may be associated to or serve one or more cells. The cells may beCAG cells or non-CAG cells, normal cells, and/or the like. The CAG cellmay be identified within the scope of a PLMN. The CAG ID may be uniquewithin the scope of a PLMN.

Example FIG. 23 and FIG. 24, depict a UE that may provide theconfiguration information of the UE to the network via a NAS message tothe AMF or via an RRC message to the NG-RAN. The AMF may perform aninitial context setup or context modification to the NG-RAN node. TheNG-RAN node may employ the information during the handover procedure.

As depicted in example FIG. 25, a handover procedure with AMFreallocation may be performed.

As depicted in example FIG. 26, a network model for hosting a Non-PublicNetwork with a PLMN infrastructure may be employed. In this model, aNon-Public Network may be deployed using the infrastructure resources ofa PLMN. Some RAN nodes may be shared by both the NPN and the PLMN so theUEs that are capable of both NPN and PLMN services may access bothnetworks through these shared RAN nodes. Besides the shared RAN nodes,the NPN may have its dedicated network functions/resources such asdedicated AMFs, dedicated Network Slices, data network, and/or the like.

As depicted in example FIG. 27, Public network integrated NPNs are NPNsmade available via PLMNs e.g., by means of dedicated DNNs, or by one (ormore) Network Slice instances allocated for the NPN or a CAG. Theexisting network slicing functionalities may apply. When an NPN is madeavailable via a PLMN, then the UE may have a subscription for the PLMN.As network slicing may not enable the possibility to prevent UEs fromtrying to access the network in areas which the UE is not allowed to usethe Network Slice allocated for the NPN, Closed Access Groups may beemployed in addition to network slicing to apply access control.

As depicted in example FIG. 28, and FIG. 29, non-public networks may berestricted for use by authorized subscribers and may not be availablefor public use. The UE may be authorized to use both a Public PLMN andnon-public networks in which case, it may possible for the UE to obtainservice continuity for services offered by Public PLMN via non-publicnetwork and vice versa.

As depicted in example FIG. 30, a network may be identified with anon-public network identifier (e.g., NPN ID, NID, and/or the like)advertised in the broadcast channels of a non-public network cell. Anon-public network may support services provided by one or more ServiceProviders (SP), which may comprise MNOs, 3rd party service provider,and/or the like. As depicted in example FIG. 30, UE #A and UE #B may beregistered to the non-public network (NPN) identified by a Non-publicnetwork ID (NPN-ID). Service provider represented by SP #1, which is aPLMN, may provide the authorized service for UE #A. Service providerrepresented by SP #N, which is 3rd party service provider, may providethe authorized service for UE #B.

In an example, a first base station may receive from a second basestation, a configuration setup message comprising a list of closedaccess group identifiers that one or more cells of the second basestation support. The first base station may receive a closed accessgroup restriction indicator indicating whether the wireless device isrestricted to cells associated with closed access groups. The first basestation may receive, from a wireless device, a measurement reportmessage comprising the measurement results of a target cell of thesecond base station. The first base station may determine a handover forthe wireless device to the target cell based on the configuration setupmessage, the measurement report, the closed access group restrictionindicator, and/or the like. The first base station may send, to thesecond base station, a request message for the handover, the requestmessage comprising an identifier of the closed access group of thewireless device, the closed access group restriction indicator, and/orthe like.

In an example, a first base station may receive from a second basestation, a configuration setup message comprising a first closed accessgroup identifier for a first cell, and/or the like. The first basestation may receive a second closed access group identifier, a closedaccess group restriction indicator, and/or the like. The first basestation may determine a handover for a wireless device to the first cellbased on the second closed access group identifier being identical tothe first closed access group identifier. The first base station maysend, to the second base station, a request message for the handover,the request message comprising the second closed access groupidentifier, the closed access group restriction indicator, and/or thelike.

In an example, a first base station may receive, from a second basestation, a configuration setup message comprising a first closed accessgroup identifier for a first cell. The first base station may receive asecond closed access group identifier and a closed access grouprestriction indicator indicating that the wireless device is restrictedto cells associated with closed access groups. The first base stationmay determine not to handover for the wireless device to the first cellbased on the closed access group restriction indicator, the secondclosed access group identifier being different from the first closedaccess group identifier, and/or the like. The first base station maysend to the second base station, a handover failure message, thehandover failure message may comprise a cause value for the handoverfailure.

In an example, a first base station may receive from a second basestation, one or more configuration setup messages comprising one or moreidentifiers corresponding to one or more cells of the second basestation, the one or more identifiers including a first closed accessgroup identifier for a first cell of the one or more cells. The firstbase station may receive a second closed access group identifierassociated with a wireless device and a closed access group restrictionindicator indicating whether the wireless device is restricted to cellsassociated with closed access groups. The first base station maydetermine whether to hand over to the second base station based on thefirst closed access group identifier, the second closed access groupidentifier, the closed access group restriction indicator, and/or thelike. The first base station may send to the second base station, arequest message for a handover to the first cell based on the closedaccess group restriction indicator indicating that the wireless deviceis restricted to cells associated with closed access groups. The requestmessage may comprise the second closed access group identifier, theclosed access group restriction indicator, and/or the like.

In an example, the sending may be further based on the first closedaccess group identifier being the same as the second closed access groupidentifier. The first base station may determine not to handover thewireless device to the first cell based on the first closed access groupidentifier being different from the second closed access groupidentifier. The first base station may determine not to handover thewireless device to the first cell based on the closed access grouprestriction indicator indicating that the wireless device is restrictedto cells associated with closed access groups, the first base stationnot supporting the second closed access group associated with thewireless device, and/or the like. The first base station may send therequest message for the handover based on the closed access grouprestriction indicator indicating that the wireless device is notrestricted to cells associated with closed access groups, the first basestation supporting the second closed access group associated with thewireless device, and/or the like. The first base station may receivefrom the second base station a second configuration setup messagecomprising an identifier for a second cell that is not associated with aclosed access group. The first base station may send to the second basestation, a request message for a handover to the second cell based onthe closed access group restriction indicator indicating that thewireless device is not restricted to cells associated with closed accessgroups.

In an example, a first base station may receive from a second basestation, one or more configuration setup messages comprising one or moreidentifiers corresponding to one or more cells of the second basestation. The one or more identifiers may include a first closed accessgroup identifier for a first cell of the one or more cells. The firstbase station may receive a second closed access group identifierassociated with a wireless device, wherein the second closed accessgroup identifier is different from the first closed access groupidentifier. The first base station may receive a closed access grouprestriction indicator indicating whether the wireless device isrestricted to cells associated with closed access groups. The first basestation may send to the second base station a request message for ahandover based on the one or more configuration setup messages furthercomprising an identifier for a second cell of the one or more cellswherein the second cell is not a closed access group cell, and/or theclosed access group restriction indicator indicating that the wirelessdevice is not restricted to cells associated with closed access groupswherein the request message may comprise the closed access grouprestriction indicator and requests a handover to the second cell.

In an example, the sending the request message for the handover to thesecond cell may be further based on the second closed access groupidentifier being different from the first closed access groupidentifier. In an example, the sending the request message for thehandover to the second cell may be further based on receiving ameasurement report from the wireless device indicating that the secondcell is a handover target cell. In an example, determining not to sendto the second base station the request message for the handover may bebased on: the second closed access group identifier being different fromthe first closed access group identifier, and/or the closed access grouprestriction indicator indicating that the wireless device is restrictedto cells associated with closed access groups. In an example, the firstbase station may determine not to send to the second base station therequest message for the handover based on the second closed access groupidentifier being different from the first closed access groupidentifier, the closed access group restriction indicator indicatingthat the wireless device is not restricted to cells associated withclosed access groups, a determination that the one or more configurationsetup messages do not include the identifier for the second cell, and/orthe like.

In an example embodiment as depicted in FIG. 31, a target base stationmay send to a source base station, a configuration setup messagecomprising a list of closed access group identifiers that one or morecells of the target base station supports. The target base station mayreceive a request for a handover to a target cell of the target basestation. The request may comprise an identifier of the closed accessgroup associated with a wireless device, a closed access grouprestriction indicator indicating whether the wireless device isrestricted to cells associated with closed access groups, and/or thelike. The target base station may determine whether to hand over to thetarget cell of the target base station based on the closed access grouprestriction indicator, the identifier of the closed access groupassociated with the wireless device, and/or the like. The source basestation may select the target base station based on the configurationsetup message. The selection of the target base station by the sourcebase station may be based on the list of closed access group identifiersthat one or more cells of the target base station supports. Theconfiguration setup message may further comprise a mapping informationfor one or more S-NSSAIs associated with one or more closed accessgroups. The configuration setup message may comprise a Xn setup message.The configuration setup message may comprise a node configuration updatemessage. The source base station may determine not to handover thewireless device to the target base station based on the closed accessgroup associated with the wireless device being different from anidentifier of the closed access group that the one or more cells of thetarget base station supports. The source base station may determine notto handover the wireless device to the first cell based on the closedaccess group restriction indicator indicating that the wireless deviceis restricted to cells associated with closed access groups, the targetbase station not supporting the closed access group associated with thewireless device, and/or the like. In an example, sending the requestmessage for the handover may be based on the closed access grouprestriction indicator indicating that the wireless device is notrestricted to cells associated with closed access groups, the first basestation supporting the second closed access group associated with thewireless device, and/or the like. The source base station may receivefrom a wireless device an RRC message. The RRC message may comprise theclosed access group restriction indicator, the identifier of the closedaccess group associated with the wireless device, and/or the like. Thesource base station may receive from an AMF, a context setup requestcomprising: the closed access group restriction indicator, theidentifier of the closed access group associated with the wirelessdevice, and/or the like. In an example, The AMF may receive from thewireless device the context setup request via a NAS message. The NASmessage may comprise the closed access group restriction indicator, theidentifier of the closed access group associated with the wirelessdevice, and/or the like. The configuration setup message may furthercomprise a served cell information NR element. The served cellinformation NR element may comprise the list of closed access groupidentifiers that one or more cells of the target base station supports,the closed access group restriction indicator, the CAG-only indicator,and/or the like. The target base station may send to the source basesstation a configuration setup response message comprising the list ofclosed access group identifiers that one or more cells of the targetbase station supports. The request message for the handover to thetarget base station may be further based on receiving a measurementreport from the wireless device indicating that the target base stationis a handover target base station. The request for a handover maycomprise a handover request message. The handover request message mayfurther comprise context information of the wireless device. The contextinformation of the wireless device may comprise the closed access grouprestriction indicator, the identifier of the closed access groupassociated with the wireless device, and/or the like.

In an example embodiment, a first base station may receive from a secondbase station, a configuration setup message comprising: a list of closedaccess group identifiers that one or more cells of the second basestation supports. The first base station may receive from an access andmobility management function a context setup request, indicating whetherthe wireless device is restricted to closed access groups (one or morerestrictions), the connection request message comprising one or moreclosed access group identifiers that the wireless devicerequested/configured. The first base station may receive from a wirelessdevice, a connection request message. The first base station maydetermine that a handover is required. The first base station may sendto the second base station based on the determining, a handover requestmessage indicating whether the wireless device is restricted to closedaccess groups (one or more restrictions). The handover request messagemay comprise the one or more closed access group identifiers that thewireless device requested/supports/configured.

In an example embodiment, a first access and mobility managementfunction may receive from a base station, a message indicating that ahandover is required, the message comprising an identifier of a closedaccess group, a closed access group restriction indicator, one or moreS-NSSAIs associated with the closed access group, and/or the like. Thefirst access and mobility management function may select a second accessand mobility management function that supports the closed access group.the first access and mobility management function may send to a secondaccess and mobility management function a handover request messagecomprising the one or more S-NSSAIs associated with the closed accessgroup, the identifier of the closed access group, the closed accessgroup restriction indicator, and/or the like. The message may furthercomprise an indication of whether the wireless device is restricted toclosed access groups (one or more restrictions). The message may furthercomprise one or more closed access group identifiers that the wirelessdevice requested.

According to various embodiments, a device such as, for example, awireless device, off-network wireless device, a base station, and/or thelike, may comprise one or more processors and memory. The memory maystore instructions that, when executed by the one or more processors,cause the device to perform a series of actions. Embodiments of exampleactions are illustrated in the accompanying figures and specification.Features from various embodiments may be combined to create yet furtherembodiments.

FIG. 33 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3310, the first base station may receive froma second base station, a message comprising a network sliceconfiguration parameter associated with a closed access group that oneor more cells of the second base station support. At 3320, the firstbase station may determine based on the network slice configurationparameter, a handover for the wireless device to a cell of the one ormore cells. At 3330, the first base station may send to the second basestation, a request message for the handover, the request messagecomprising an identifier of the closed access group of the wirelessdevice.

In an example, the first base station may select the second base stationbased on the network slice configuration parameter associated with theclosed access group that the one or more cells of the second basestation support. In an example, the first base station may receive aradio resource control (RRC) message comprising mapping information forone or more single network slice selection assistance informations(S-NSSAIs) associated with the closed access group, or a defaultconfigured NSSAI indication for the closed access group. In an example,the first base station may receive from an access and mobilitymanagement function (AMF), a context setup request comprising: mappinginformation for one or more single network slice selection assistanceinformations (S-NSSAIs) associated with the closed access group, or adefault configured NSSAI indication for the closed access group.

In an example, the message may comprise mapping information for one ormore single network slice selection assistance informations (S-NSSAIs)associated with one or more closed access groups. In an example, themessage may be a Xn setup message, a node configuration update message,and/or the like. In an example, the message may comprise a served cellinformation new radio (NR) element, wherein the served cell informationNR element may comprise a list of closed access group identifiers thatone or more cells of the second base station supports.

In an example, the first base station may send to the second basestation, a configuration setup response message comprising a networkslice configuration parameter associated with a closed access group thatone or more cells of the first base station support.

In an example, the request for a handover may be a handover requestmessage comprising context information of the wireless device. Thecontext information of the wireless device may comprise a closed accessgroup restriction indicator, an identifier of the closed access group.

In an example, the closed access group may be associated with anon-public network.

FIG. 34 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3410, a first access and mobility managementfunction may receive from a base station, a message indicating that ahandover is required, the message comprising an identifier of a closedaccess group. At 3420, the first access and mobility management functionmay select a second access and mobility management function thatsupports the closed access group. At 3430, the first access and mobilitymanagement function may send to the second access and mobilitymanagement function a handover request message comprising a networkslice configuration parameter associated with the closed access group.

In an example, the message may further comprise an indication of whetherthe wireless device is restricted to closed access groups (one or morerestrictions). In an example, the message may comprise one or moreclosed access group identifiers that the wireless device requested. Themessage may comprise an identifier of a non-public network. In anexample, the message may comprise mapping information for one or moresingle network slice selection assistance informations (S-NSSAIs)associated with the closed access group.

In an example, the selection may be based on the indication. In anexample, the selection may be based on the second access and mobilitymanagement function supporting a non-public network.

In an example, the handover request message may comprise a network sliceconfiguration parameter for a non-public network.

In an example, the first access and mobility management function mayreceive from the second access and mobility management function, aresponse message indicating acceptance of the request.

In this specification, a and an and similar phrases are to beinterpreted as at least one and one or more. In this specification, theterm may is to be interpreted as may, for example. In other words, theterm may is indicative that the phrase following the term may is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments. If A and Bare sets and every element of A is also an element of B, A is called asubset of B. In this specification, only non-empty sets and subsets areconsidered. For example, possible subsets of B={cell1, cell2} are:{cell1}, {cell2}, and {cell1, cell2}.

In this specification, parameters (Information elements: IEs) maycomprise one or more objects, and each of those objects may comprise oneor more other objects. For example, if parameter (IE) N comprisesparameter (IE) M, and parameter (IE) M comprises parameter (IE) K, andparameter (IE) K comprises parameter (information element) J, then, forexample, N comprises K, and N comprises J. In an example embodiment,when one or more messages comprise a plurality of parameters, it impliesthat a parameter in the plurality of parameters is in at least one ofthe one or more messages, but does not have to be in each of the one ormore messages.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e hardware with a biological element) or acombination thereof, which may be behaviorally equivalent. For example,modules may be implemented as a software routine written in a computerlanguage configured to be executed by a hardware machine (such as C,C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally, it may be possible to implement modules using physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware comprise:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed using languages such as assembly, C,C++ or the like. FPGAs, ASICs and CPLDs are often programmed usinghardware description languages (HDL) such as VHSIC hardware descriptionlanguage (VHDL) or Verilog that configure connections between internalhardware modules with lesser functionality on a programmable device.Finally, it needs to be emphasized that the above mentioned technologiesare often employed in combination to achieve the result of a functionalmodule.

Example embodiments of the invention may be implemented using variousphysical and/or virtual network elements, software defined networking,virtual network functions.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using 5G AN. However, one skilled in the art will recognize thatembodiments of the invention may also be implemented in a systemcomprising one or more legacy systems or LTE. The disclosed methods andsystems may be implemented in wireless or wireline systems. The featuresof various embodiments presented in this invention may be combined. Oneor many features (method or system) of one embodiment may be implementedin other embodiments. A limited number of example combinations are shownto indicate to one skilled in the art the possibility of features thatmay be combined in various embodiments to create enhanced transmissionand reception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposes.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or optionally usedin some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language means for or step for be interpreted under 35 U.S.C.112. Claims that do not expressly include the phrase means for or stepfor are not to be interpreted under 35 U.S.C. 112.

What is claimed is:
 1. A method comprising: receiving, by a first basestation from a second base station, a next generation radio accessnetwork (NG-RAN) configuration update message comprising parameters ofone or more cells of the second base station, wherein the parametersindicate: a neighbor information evolved universal mobiletelecommunications system terrestrial radio access (E-UTRA) informationelement (IE); and a served cells new radio (NR) to add IE comprising: aslice identifier of a first network slice supported by a cell of the oneor more cells of the second base station; and an NR physical cellidentifier (NR-PCI) of the cell; sending, by the first base station tothe second base station, in response to receiving the served cells NR toadd IE, an NG-RAN configuration update acknowledge message comprising aserved cell information NR IE indicating that the cell is in a firstclosed access group (CAG); receiving, by the first base station from awireless device, one or more messages comprising: an identifier of thecell of the second base station; a measurement report of a signalstrength for the cell; a slice identifier of the first network slice;and an indication that the wireless device is allowed to access thefirst CAG; determining, by the first base station, to send a handoverrequest message for handover of the wireless device to the first cell ofthe second base station based on: the measurement report received fromthe wireless device; and the cell being in the first CAG; and sending,to the second base station, the handover request message, wherein thehandover request message comprises an identifier of the cell.
 2. Themethod of claim 1, further comprising selecting, by the first basestation, the second base station based on the parameters.
 3. The methodof claim 1, wherein the NG-RAN configuration update message furthercomprises mapping information of the slice identifier to one or moreCAGs.
 4. The method of claim 1, further comprising receiving, by thefirst base station, a radio resource control (RRC) message mappinginformation for one or more slice identifiers associated with the firstCAG.
 5. The method of claim 1, further comprising receiving, by thefirst base station, a radio resource control (RRC) message comprising adefault configured slice identifier indication for the first CAG.
 6. Themethod of claim 1, further comprising receiving, by the first basestation, from an access and mobility management function (AMF), acontext setup request comprising: mapping information for one or moreslice identifiers associated with the first CAG; or a default configuredslice identifier indication for the first CAG.
 7. The method of claim 1,wherein the served cell information NR IE comprises a list of CAGidentifiers that one or more cells of the first base station support. 8.The method of claim 1, wherein the NG-RAN configuration updateacknowledge message comprises a network slice configuration parameterassociated with a CAG that one or more cells of the first base stationsupport.
 9. The method of claim 1, wherein the handover request messagecomprises context information of the wireless device, wherein thecontext information of the wireless device comprises: a CAG restrictionindicator; and an identifier of the first CAG.
 10. The method of claim1, wherein the first CAG is associated with a non-public network.
 11. Afirst base station comprising: one or more processors; memory storinginstructions that, when executed by the one or more processors, causethe first base station to: receive, from a second base station, a nextgeneration radio access network (NG-RAN) configuration update messagecomprising parameters of one or more cells of the second base station,wherein the parameters indicate: a neighbor information evolveduniversal mobile telecommunications system terrestrial radio access(E-UTRA) information element (IE); and a served cells new radio (NR) toadd IE comprising: a slice identifier of a first network slice supportedby a cell of the one or more cells of the second base station; and an NRphysical cell identifier (NR-PCI) of the cell; send, to the second basestation, in response to receiving the served cells NR to add IE, anNG-RAN configuration update acknowledge message comprising a served cellinformation NR IE indicating that the cell is in a first closed accessgroup (CAG); receive, from a wireless device, one or more messagescomprising: an identifier of the cell of the second base station; ameasurement report of a signal strength for the cell; a slice identifierof the first network slice; and an indication that the wireless deviceis allowed to access the first CAG; determine, by the first basestation, to send a handover request message for handover of the wirelessdevice to the cell of the second base station based on: the measurementreport received from the wireless device; and the cell being in thefirst CAG; and send, to the second base station, the handover requestmessage, wherein the handover request message comprises an identifier ofthe cell.
 12. The first base station of claim 11, wherein theinstructions, when executed by the one or more processors, further causethe first base station to select the second base station based on theparameters.
 13. The first base station of claim 11, wherein the NG-RANconfiguration update message further comprises mapping information ofthe slice identifier to one or more CAGs.
 14. The first base station ofclaim 11, wherein the instructions, when executed by the one or moreprocessors, further cause the first base station to receive a radioresource control (RRC) message mapping information for one or more sliceidentifiers associated with the first CAG.
 15. The first base station ofclaim 11, wherein the instructions, when executed by the one or moreprocessors, further cause the first base station to receive a radioresource control (RRC) message comprising a default configured sliceidentifier indication for the first CAG.
 16. The first base station ofclaim 11, wherein the instructions, when executed by the one or moreprocessors, further cause the first base station to receive, from anaccess and mobility management function (AMF), a context setup requestcomprising: mapping information for one or more slice identifiersassociated with the first CAG; or a default configured slice identifierindication for the first CAG.
 17. The first base station of claim 11,wherein the served cell information NR IE comprises a list of CAGidentifiers that one or more cells of the first base station support.18. The first base station of claim 11, wherein the NG-RAN configurationupdate acknowledge message comprises a network slice configurationparameter associated with a CAG that one or more cells of the first basestation support.
 19. The first base station of claim 11, wherein thehandover request message comprises context information of the wirelessdevice, wherein the context information of the wireless devicecomprises: a CAG restriction indicator; and an identifier of the firstCAG.
 20. A system comprising: a first base station comprising: one ormore first processors; a first memory storing first instructions that,when executed by the one or more first processors, cause the first basestation to: receive, from a second base station, a next generation radioaccess network (NG-RAN) configuration update message comprisingparameters of one or more cells of the second base station, wherein theparameters indicate: a neighbor information evolved universal mobiletelecommunications system terrestrial radio access (E-UTRA) informationelement (IE); and a served cells new radio (NR) to add IE comprising: aslice identifier of a first network slice supported by a cell of the oneor more cells of the second base station; and an NR physical cellidentifier (NR-PCI) of the cell; send, to the second base station, inresponse to receiving the served cells NR to add IE, an NG-RANconfiguration update acknowledge message comprising a served cellinformation NR IE indicating that the cell is in a first closed accessgroup (CAG); receive, from a wireless device, one or more messagescomprising: an identifier of the cell of the second base station; ameasurement report of a signal strength for the cell; a slice identifierof the first network slice; and an indication that the wireless deviceis allowed to access the first CAG; determine, by the first basestation, to send a handover request message for handover of the wirelessdevice to the cell of the second base station based on: the measurementreport received from the wireless device; and the cell being in thefirst CAG; and send, to the second base station, the handover requestmessage, wherein the handover request message comprises an identifier ofthe cell; and the second base station, wherein the second base stationcomprises: one or more second processors; a second memory storing secondinstructions that, when executed by the one or more second processors,cause the second base station to: send, to the first base station, theNG-RAN configuration update message comprising the parameters; receive,from the first base station, the NG-RAN configuration update acknowledgemessage; and receive, from the first base station, the handover requestmessage.